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dec8ced8 |
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05-Mar-2024 |
Namhyung Kim <namhyung@kernel.org> |
perf/x86: Fix out of range data On x86 each struct cpu_hw_events maintains a table for counter assignment but it missed to update one for the deleted event in x86_pmu_del(). This can make perf_clear_dirty_counters() reset used counter if it's called before event scheduling or enabling. Then it would return out of range data which doesn't make sense. The following code can reproduce the problem. $ cat repro.c #include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <linux/perf_event.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/syscall.h> struct perf_event_attr attr = { .type = PERF_TYPE_HARDWARE, .config = PERF_COUNT_HW_CPU_CYCLES, .disabled = 1, }; void *worker(void *arg) { int cpu = (long)arg; int fd1 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0); int fd2 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0); void *p; do { ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0); p = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd1, 0); ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0); ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0); munmap(p, 4096); ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0); } while (1); return NULL; } int main(void) { int i; int n = sysconf(_SC_NPROCESSORS_ONLN); pthread_t *th = calloc(n, sizeof(*th)); for (i = 0; i < n; i++) pthread_create(&th[i], NULL, worker, (void *)(long)i); for (i = 0; i < n; i++) pthread_join(th[i], NULL); free(th); return 0; } And you can see the out of range data using perf stat like this. Probably it'd be easier to see on a large machine. $ gcc -o repro repro.c -pthread $ ./repro & $ sudo perf stat -A -I 1000 2>&1 | awk '{ if (length($3) > 15) print }' 1.001028462 CPU6 196,719,295,683,763 cycles # 194290.996 GHz (71.54%) 1.001028462 CPU3 396,077,485,787,730 branch-misses # 15804359784.80% of all branches (71.07%) 1.001028462 CPU17 197,608,350,727,877 branch-misses # 14594186554.56% of all branches (71.22%) 2.020064073 CPU4 198,372,472,612,140 cycles # 194681.113 GHz (70.95%) 2.020064073 CPU6 199,419,277,896,696 cycles # 195720.007 GHz (70.57%) 2.020064073 CPU20 198,147,174,025,639 cycles # 194474.654 GHz (71.03%) 2.020064073 CPU20 198,421,240,580,145 stalled-cycles-frontend # 100.14% frontend cycles idle (70.93%) 3.037443155 CPU4 197,382,689,923,416 cycles # 194043.065 GHz (71.30%) 3.037443155 CPU20 196,324,797,879,414 cycles # 193003.773 GHz (71.69%) 3.037443155 CPU5 197,679,956,608,205 stalled-cycles-backend # 1315606428.66% backend cycles idle (71.19%) 3.037443155 CPU5 198,571,860,474,851 instructions # 13215422.58 insn per cycle It should move the contents in the cpuc->assign as well. Fixes: 5471eea5d3bf ("perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240306061003.1894224-1-namhyung@kernel.org
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#
1f2376cd |
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25-Oct-2023 |
Kan Liang <kan.liang@linux.intel.com> |
perf: Add branch_sample_call_stack Add a helper function to check call stack sample type. The later patch will invoke the function in several places. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20231025201626.3000228-3-kan.liang@linux.intel.com
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#
571d91dc |
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25-Oct-2023 |
Kan Liang <kan.liang@linux.intel.com> |
perf: Add branch stack counters Currently, the additional information of a branch entry is stored in a u64 space. With more and more information added, the space is running out. For example, the information of occurrences of events will be added for each branch. Two places were suggested to append the counters. https://lore.kernel.org/lkml/20230802215814.GH231007@hirez.programming.kicks-ass.net/ One place is right after the flags of each branch entry. It changes the existing struct perf_branch_entry. The later ARCH specific implementation has to be really careful to consistently pick the right struct. The other place is right after the entire struct perf_branch_stack. The disadvantage is that the pointer of the extra space has to be recorded. The common interface perf_sample_save_brstack() has to be updated. The latter is much straightforward, and should be easily understood and maintained. It is implemented in the patch. Add a new branch sample type, PERF_SAMPLE_BRANCH_COUNTERS, to indicate the event which is recorded in the branch info. The "u64 counters" may store the occurrences of several events. The information regarding the number of events/counters and the width of each counter should be exposed via sysfs as a reference for the perf tool. Define the branch_counter_nr and branch_counter_width ABI here. The support will be implemented later in the Intel-specific patch. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20231025201626.3000228-1-kan.liang@linux.intel.com
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#
b0560bfd |
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29-Aug-2023 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Clean up the hybrid CPU type handling code There is a fairly long list of grievances about the current code. The main beefs: 1. hybrid_big_small assumes that the *HARDWARE* (CPUID) provided core types are a bitmap. They are not. If Intel happened to make a core type of 0xff, hilarity would ensue. 2. adl_get_hybrid_cpu_type() utterly inscrutable. There are precisely zero comments and zero changelog about what it is attempting to do. According to Kan, the adl_get_hybrid_cpu_type() is there because some Alder Lake (ADL) CPUs can do some silly things. Some ADL models are *supposed* to be hybrid CPUs with big and little cores, but there are some SKUs that only have big cores. CPUID(0x1a) on those CPUs does not say that the CPUs are big cores. It apparently just returns 0x0. It confuses perf because it expects to see either 0x40 (Core) or 0x20 (Atom). The perf workaround for this is to watch for a CPU core saying it is type 0x0. If that happens on an Alder Lake, it calls x86_pmu.get_hybrid_cpu_type() and just assumes that the core is a Core (0x40) CPU. To fix up the mess, separate out the CPU types and the 'pmu' types. This allows 'hybrid_pmu_type' bitmaps without worrying that some future CPU type will set multiple bits. Since the types are now separate, add a function to glue them back together again. Actual comment on the situation in the glue function (find_hybrid_pmu_for_cpu()). Also, give ->get_hybrid_cpu_type() a real return type and make it clear that it is overriding the *CPU* type, not the PMU type. Rename cpu_type to pmu_type in the struct x86_hybrid_pmu to reflect the change. Originally-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230829125806.3016082-6-kan.liang@linux.intel.com
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#
4b36873b |
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24-Jul-2023 |
James Clark <james.clark@arm.com> |
perf/x86: Remove unused PERF_PMU_CAP_HETEROGENEOUS_CPUS capability Since commit bd2756811766 ("perf: Rewrite core context handling") the relationship between perf_event_context and PMUs has changed so that the error scenario that PERF_PMU_CAP_HETEROGENEOUS_CPUS originally silenced no longer exists. Remove the capability to avoid confusion that it actually influences any perf core behavior. This change should be a no-op. Signed-off-by: James Clark <james.clark@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20230724134500.970496-3-james.clark@arm.com
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#
4c1c9dea |
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06-Jul-2023 |
Uros Bizjak <ubizjak@gmail.com> |
perf/x86: Use local64_try_cmpxchg Use local64_try_cmpxchg instead of local64_cmpxchg (*ptr, old, new) == old. x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails. There is no need to re-read the value in the loop. No functional change intended. Cc. "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20230706141720.2672-1-ubizjak@gmail.com
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#
90befef5 |
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26-Apr-2023 |
Namhyung Kim <namhyung@kernel.org> |
perf/x86: Fix missing sample size update on AMD BRS It missed to convert a PERF_SAMPLE_BRANCH_STACK user to call the new perf_sample_save_brstack() helper in order to update the dyn_size. This affects AMD Zen3 machines with the branch-brs event. Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20230427030527.580841-1-namhyung@kernel.org
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#
4b4191b8 |
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08-Feb-2023 |
Sean Christopherson <seanjc@google.com> |
perf/x86: Refuse to export capabilities for hybrid PMUs Now that KVM disables vPMU support on hybrid CPUs, WARN and return zeros if perf_get_x86_pmu_capability() is invoked on a hybrid CPU. The helper doesn't provide an accurate accounting of the PMU capabilities for hybrid CPUs and needs to be enhanced if KVM, or anything else outside of perf, wants to act on the PMU capabilities. Cc: stable@vger.kernel.org Cc: Andrew Cooper <Andrew.Cooper3@citrix.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Link: https://lore.kernel.org/all/20220818181530.2355034-1-kan.liang@linux.intel.com Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20230208204230.1360502-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
8e356858 |
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28-Oct-2022 |
Rafael Mendonca <rafaelmendsr@gmail.com> |
perf/x86: Remove unused variable 'cpu_type' Since the removal of function x86_pmu_update_cpu_context() by commit 983bd8543b5a ("perf: Rewrite core context handling"), there is no need to query the type of the hybrid CPU inside function init_hw_perf_events(). Fixes: 983bd8543b5a ("perf: Rewrite core context handling") Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221028203006.976831-1-rafaelmendsr@gmail.com
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#
bd275681 |
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08-Oct-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf: Rewrite core context handling There have been various issues and limitations with the way perf uses (task) contexts to track events. Most notable is the single hardware PMU task context, which has resulted in a number of yucky things (both proposed and merged). Notably: - HW breakpoint PMU - ARM big.little PMU / Intel ADL PMU - Intel Branch Monitoring PMU - AMD IBS PMU - S390 cpum_cf PMU - PowerPC trace_imc PMU *Current design:* Currently we have a per task and per cpu perf_event_contexts: task_struct::perf_events_ctxp[] <-> perf_event_context <-> perf_cpu_context ^ | ^ | ^ `---------------------------------' | `--> pmu ---' v ^ perf_event ------' Each task has an array of pointers to a perf_event_context. Each perf_event_context has a direct relation to a PMU and a group of events for that PMU. The task related perf_event_context's have a pointer back to that task. Each PMU has a per-cpu pointer to a per-cpu perf_cpu_context, which includes a perf_event_context, which again has a direct relation to that PMU, and a group of events for that PMU. The perf_cpu_context also tracks which task context is currently associated with that CPU and includes a few other things like the hrtimer for rotation etc. Each perf_event is then associated with its PMU and one perf_event_context. *Proposed design:* New design proposed by this patch reduce to a single task context and a single CPU context but adds some intermediate data-structures: task_struct::perf_event_ctxp -> perf_event_context <- perf_cpu_context ^ | ^ ^ `---------------------------' | | | | perf_cpu_pmu_context <--. | `----. ^ | | | | | | v v | | ,--> perf_event_pmu_context | | | | | | | v v | perf_event ---> pmu ----------------' With the new design, perf_event_context will hold all events for all pmus in the (respective pinned/flexible) rbtrees. This can be achieved by adding pmu to rbtree key: {cpu, pmu, cgroup, group_index} Each perf_event_context carries a list of perf_event_pmu_context which is used to hold per-pmu-per-context state. For example, it keeps track of currently active events for that pmu, a pmu specific task_ctx_data, a flag to tell whether rotation is required or not etc. Additionally, perf_cpu_pmu_context is used to hold per-pmu-per-cpu state like hrtimer details to drive the event rotation, a pointer to perf_event_pmu_context of currently running task and some other ancillary information. Each perf_event is associated to it's pmu, perf_event_context and perf_event_pmu_context. Further optimizations to current implementation are possible. For example, ctx_resched() can be optimized to reschedule only single pmu events. Much thanks to Ravi for picking this up and pushing it towards completion. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221008062424.313-1-ravi.bangoria@amd.com
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#
dbf4e792 |
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20-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86/p4: Remove perfctr_second_write quirk Now that we have a x86_pmu::set_period() method, use it to remove the perfctr_second_write quirk from the generic code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220829101321.839502514@infradead.org
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#
08b3068f |
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10-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Add a x86_pmu::limit_period static_call Avoid a branch and indirect call. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220829101321.640658334@infradead.org
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#
28f0f3c4 |
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10-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Change x86_pmu::limit_period signature In preparation for making it a static_call, change the signature. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220829101321.573713839@infradead.org
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e577bb17 |
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10-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86/intel: Move the topdown stuff into the intel driver Use the new x86_pmu::{set_period,update}() methods to push the topdown stuff into the Intel driver, where it belongs. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220829101321.505933457@infradead.org
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#
73759c34 |
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10-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Add two more x86_pmu methods In order to clean up x86_perf_event_{set_period,update)() start by adding them as x86_pmu methods. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220829101321.440196408@infradead.org
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#
a9a931e2 |
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01-Sep-2022 |
Kan Liang <kan.liang@linux.intel.com> |
perf: Use sample_flags for branch stack Use the new sample_flags to indicate whether the branch stack is filled by the PMU driver. Remove the br_stack from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-4-kan.liang@linux.intel.com
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#
916e3a4f |
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01-Jun-2022 |
Paolo Bonzini <pbonzini@redhat.com> |
x86: events: Do not return bogus capabilities if PMU is broken If the PMU is broken due to firmware issues, check_hw_exists() will return false but perf_get_x86_pmu_capability() will still return data from x86_pmu. Likewise if some of the hotplug callbacks cannot be installed the contents of x86_pmu will not be reverted. Handle the failure in both cases by clearing x86_pmu if init_hw_perf_events() or reverts to software events only. Co-developed-by: Like Xu <likexu@tencent.com> Signed-off-by: Like Xu <likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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#
dc852ff5 |
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18-May-2022 |
Like Xu <likexu@tencent.com> |
perf: x86/core: Add interface to query perfmon_event_map[] directly Currently, we have [intel|knc|p4|p6]_perfmon_event_map on the Intel platforms and amd_[f17h]_perfmon_event_map on the AMD platforms. Early clumsy KVM code or other potential perf_event users may have hard-coded these perfmon_maps (e.g., arch/x86/kvm/svm/pmu.c), so it would not make sense to program a common hardware event based on the generic "enum perf_hw_id" once the two tables do not match. Let's provide an interface for callers outside the perf subsystem to get the counter config based on the perfmon_event_map currently in use, and it also helps to save bytes. Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Like Xu <likexu@tencent.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Message-Id: <20220518132512.37864-10-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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39a4d779 |
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11-Apr-2022 |
Like Xu <like.xu@linux.intel.com> |
perf/x86/core: Pass "struct kvm_pmu *" to determine the guest values Splitting the logic for determining the guest values is unnecessarily confusing, and potentially fragile. Perf should have full knowledge and control of what values are loaded for the guest. If we change .guest_get_msrs() to take a struct kvm_pmu pointer, then it can generate the full set of guest values by grabbing guest ds_area and pebs_data_cfg. Alternatively, .guest_get_msrs() could take the desired guest MSR values directly (ds_area and pebs_data_cfg), but kvm_pmu is vendor agnostic, so we don't see any reason to not just pass the pointer. Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Like Xu <like.xu@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Message-Id: <20220411101946.20262-4-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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fb358e0b |
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11-Apr-2022 |
Like Xu <likexu@tencent.com> |
perf/x86/intel: Add EPT-Friendly PEBS for Ice Lake Server Add support for EPT-Friendly PEBS, a new CPU feature that enlightens PEBS to translate guest linear address through EPT, and facilitates handling VM-Exits that occur when accessing PEBS records. More information can be found in the December 2021 release of Intel's SDM, Volume 3, 18.9.5 "EPT-Friendly PEBS". This new hardware facility makes sure the guest PEBS records will not be lost, which is available on Intel Ice Lake Server platforms (and later). KVM will check this field through perf_get_x86_pmu_capability() instead of hard coding the CPU models in the KVM code. If it is supported, the guest PEBS capability will be exposed to the guest. Guest PEBS can be enabled when and only when "EPT-Friendly PEBS" is supported and EPT is enabled. Cc: linux-perf-users@vger.kernel.org Signed-off-by: Like Xu <likexu@tencent.com> Message-Id: <20220411101946.20262-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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3c27b0c6 |
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10-May-2022 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86/amd: Fix AMD BRS period adjustment There's two problems with the current amd_brs_adjust_period() code: - it isn't in fact AMD specific and wil always adjust the period; - it adjusts the period, while it should only adjust the event count, resulting in repoting a short period. Fix this by using x86_pmu.limit_period, this makes it specific to the AMD BRS case and ensures only the event count is adjusted while the reported period is unmodified. Fixes: ba2fe7500845 ("perf/x86/amd: Add AMD branch sampling period adjustment") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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#
7bebfe9d |
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23-Mar-2022 |
Yang Jihong <yangjihong1@huawei.com> |
perf/x86: Unify format of events sysfs show Sysfs show formats of files in /sys/devices/cpu/events/ are not unified, some end with "\n", and some do not. Modify sysfs show format of events defined by EVENT_ATTR_STR to end with "\n". Before: $ ls /sys/devices/cpu/events/* | xargs -i sh -c 'echo -n "{}: "; cat -A {}; echo' branch-instructions: event=0xc4$ branch-misses: event=0xc5$ bus-cycles: event=0x3c,umask=0x01$ cache-misses: event=0x2e,umask=0x41$ cache-references: event=0x2e,umask=0x4f$ cpu-cycles: event=0x3c$ instructions: event=0xc0$ ref-cycles: event=0x00,umask=0x03$ slots: event=0x00,umask=0x4 topdown-bad-spec: event=0x00,umask=0x81 topdown-be-bound: event=0x00,umask=0x83 topdown-fe-bound: event=0x00,umask=0x82 topdown-retiring: event=0x00,umask=0x80 After: $ ls /sys/devices/cpu/events/* | xargs -i sh -c 'echo -n "{}: "; cat -A {}; echo' /sys/devices/cpu/events/branch-instructions: event=0xc4$ /sys/devices/cpu/events/branch-misses: event=0xc5$ /sys/devices/cpu/events/bus-cycles: event=0x3c,umask=0x01$ /sys/devices/cpu/events/cache-misses: event=0x2e,umask=0x41$ /sys/devices/cpu/events/cache-references: event=0x2e,umask=0x4f$ /sys/devices/cpu/events/cpu-cycles: event=0x3c$ /sys/devices/cpu/events/instructions: event=0xc0$ /sys/devices/cpu/events/ref-cycles: event=0x00,umask=0x03$ /sys/devices/cpu/events/slots: event=0x00,umask=0x4$ Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220324031957.135595-1-yangjihong1@huawei.com
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ba2fe750 |
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22-Mar-2022 |
Stephane Eranian <eranian@google.com> |
perf/x86/amd: Add AMD branch sampling period adjustment Add code to adjust the sampling event period when used with the Branch Sampling feature (BRS). Given the depth of the BRS (16), the period is reduced by that depth such that in the best case scenario, BRS saturates at the desired sampling period. In practice, though, the processor may execute more branches. Given a desired period P and a depth D, the kernel programs the actual period at P - D. After P occurrences of the sampling event, the counter overflows. It then may take X branches (skid) before the NMI is caught and held by the hardware and BRS activates. Then, after D branches, BRS saturates and the NMI is delivered. With no skid, the effective period would be (P - D) + D = P. In practice, however, it will likely be (P - D) + X + D. There is no way to eliminate X or predict X. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220322221517.2510440-7-eranian@google.com
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ada54345 |
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22-Mar-2022 |
Stephane Eranian <eranian@google.com> |
perf/x86/amd: Add AMD Fam19h Branch Sampling support Add support for the AMD Fam19h 16-deep branch sampling feature as described in the AMD PPR Fam19h Model 01h Revision B1. This is a model specific extension. It is not an architected AMD feature. The Branch Sampling (BRS) operates with a 16-deep saturating buffer in MSR registers. There is no branch type filtering. All control flow changes are captured. BRS relies on specific programming of the core PMU of Fam19h. In particular, the following requirements must be met: - the sampling period be greater than 16 (BRS depth) - the sampling period must use a fixed and not frequency mode BRS interacts with the NMI interrupt as well. Because enabling BRS is expensive, it is only activated after P event occurrences, where P is the desired sampling period. At P occurrences of the event, the counter overflows, the CPU catches the interrupt, activates BRS for 16 branches until it saturates, and then delivers the NMI to the kernel. Between the overflow and the time BRS activates more branches may be executed skewing the period. All along, the sampling event keeps counting. The skid may be attenuated by reducing the sampling period by 16 (subsequent patch). BRS is integrated into perf_events seamlessly via the same PERF_RECORD_BRANCH_STACK sample format. BRS generates perf_branch_entry records in the sampling buffer. No prediction information is supported. The branches are stored in reverse order of execution. The most recent branch is the first entry in each record. No modification to the perf tool is necessary. BRS can be used with any sampling event. However, it is recommended to use the RETIRED_BRANCH_INSTRUCTIONS event because it matches what the BRS captures. $ perf record -b -c 1000037 -e cpu/event=0xc2,name=ret_br_instructions/ test $ perf report -D 56531696056126 0x193c000 [0x1a8]: PERF_RECORD_SAMPLE(IP, 0x2): 18122/18230: 0x401d24 period: 1000037 addr: 0 ... branch stack: nr:16 ..... 0: 0000000000401d24 -> 0000000000401d5a 0 cycles 0 ..... 1: 0000000000401d5c -> 0000000000401d24 0 cycles 0 ..... 2: 0000000000401d22 -> 0000000000401d5c 0 cycles 0 ..... 3: 0000000000401d5e -> 0000000000401d22 0 cycles 0 ..... 4: 0000000000401d20 -> 0000000000401d5e 0 cycles 0 ..... 5: 0000000000401d3e -> 0000000000401d20 0 cycles 0 ..... 6: 0000000000401d42 -> 0000000000401d3e 0 cycles 0 ..... 7: 0000000000401d3c -> 0000000000401d42 0 cycles 0 ..... 8: 0000000000401d44 -> 0000000000401d3c 0 cycles 0 ..... 9: 0000000000401d3a -> 0000000000401d44 0 cycles 0 ..... 10: 0000000000401d46 -> 0000000000401d3a 0 cycles 0 ..... 11: 0000000000401d38 -> 0000000000401d46 0 cycles 0 ..... 12: 0000000000401d48 -> 0000000000401d38 0 cycles 0 ..... 13: 0000000000401d36 -> 0000000000401d48 0 cycles 0 ..... 14: 0000000000401d4a -> 0000000000401d36 0 cycles 0 ..... 15: 0000000000401d34 -> 0000000000401d4a 0 cycles 0 ... thread: test:18230 ...... dso: test Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220322221517.2510440-4-eranian@google.com
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36903abe |
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15-Feb-2022 |
Arnd Bergmann <arnd@arndb.de> |
x86: remove __range_not_ok() The __range_not_ok() helper is an x86 (and sparc64) specific interface that does roughly the same thing as __access_ok(), but with different calling conventions. Change this to use the normal interface in order for consistency as we clean up all access_ok() implementations. This changes the limit from TASK_SIZE to TASK_SIZE_MAX, which Al points out is the right thing do do here anyway. The callers have to use __access_ok() instead of the normal access_ok() though, because on x86 that contains a WARN_ON_IN_IRQ() check that cannot be used inside of NMI context while tracing. The check in copy_code() is not needed any more, because this one is already done by copy_from_user_nmi(). Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Suggested-by: Christoph Hellwig <hch@infradead.org> Link: https://lore.kernel.org/lkml/YgsUKcXGR7r4nINj@zeniv-ca.linux.org.uk/ Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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1c343051 |
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10-Nov-2021 |
Sean Christopherson <seanjc@google.com> |
perf: Add wrappers for invoking guest callbacks Add helpers for the guest callbacks to prepare for burying the callbacks behind a Kconfig (it's a lot easier to provide a few stubs than to #ifdef piles of code), and also to prepare for converting the callbacks to static_call(). perf_instruction_pointer() in particular will have subtle semantics with static_call(), as the "no callbacks" case will return 0 if the callbacks are unregistered between querying guest state and getting the IP. Implement the change now to avoid a functional change when adding static_call() support, and because the new helper needs to return _something_ in this case. Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20211111020738.2512932-8-seanjc@google.com
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b9f5621c |
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10-Nov-2021 |
Like Xu <like.xu@linux.intel.com> |
perf/core: Rework guest callbacks to prepare for static_call support To prepare for using static_calls to optimize perf's guest callbacks, replace ->is_in_guest and ->is_user_mode with a new multiplexed hook ->state, tweak ->handle_intel_pt_intr to play nice with being called when there is no active guest, and drop "guest" from ->get_guest_ip. Return '0' from ->state and ->handle_intel_pt_intr to indicate "not in guest" so that DEFINE_STATIC_CALL_RET0 can be used to define the static calls, i.e. no callback == !guest. [sean: extracted from static_call patch, fixed get_ip() bug, wrote changelog] Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Like Xu <like.xu@linux.intel.com> Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/20211111020738.2512932-7-seanjc@google.com
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ff083a2d |
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10-Nov-2021 |
Sean Christopherson <seanjc@google.com> |
perf: Protect perf_guest_cbs with RCU Protect perf_guest_cbs with RCU to fix multiple possible errors. Luckily, all paths that read perf_guest_cbs already require RCU protection, e.g. to protect the callback chains, so only the direct perf_guest_cbs touchpoints need to be modified. Bug #1 is a simple lack of WRITE_ONCE/READ_ONCE behavior to ensure perf_guest_cbs isn't reloaded between a !NULL check and a dereference. Fixed via the READ_ONCE() in rcu_dereference(). Bug #2 is that on weakly-ordered architectures, updates to the callbacks themselves are not guaranteed to be visible before the pointer is made visible to readers. Fixed by the smp_store_release() in rcu_assign_pointer() when the new pointer is non-NULL. Bug #3 is that, because the callbacks are global, it's possible for readers to run in parallel with an unregisters, and thus a module implementing the callbacks can be unloaded while readers are in flight, resulting in a use-after-free. Fixed by a synchronize_rcu() call when unregistering callbacks. Bug #1 escaped notice because it's extremely unlikely a compiler will reload perf_guest_cbs in this sequence. perf_guest_cbs does get reloaded for future derefs, e.g. for ->is_user_mode(), but the ->is_in_guest() guard all but guarantees the consumer will win the race, e.g. to nullify perf_guest_cbs, KVM has to completely exit the guest and teardown down all VMs before KVM start its module unload / unregister sequence. This also makes it all but impossible to encounter bug #3. Bug #2 has not been a problem because all architectures that register callbacks are strongly ordered and/or have a static set of callbacks. But with help, unloading kvm_intel can trigger bug #1 e.g. wrapping perf_guest_cbs with READ_ONCE in perf_misc_flags() while spamming kvm_intel module load/unload leads to: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 1825 Comm: stress Not tainted 5.14.0-rc2+ #459 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:perf_misc_flags+0x1c/0x70 Call Trace: perf_prepare_sample+0x53/0x6b0 perf_event_output_forward+0x67/0x160 __perf_event_overflow+0x52/0xf0 handle_pmi_common+0x207/0x300 intel_pmu_handle_irq+0xcf/0x410 perf_event_nmi_handler+0x28/0x50 nmi_handle+0xc7/0x260 default_do_nmi+0x6b/0x170 exc_nmi+0x103/0x130 asm_exc_nmi+0x76/0xbf Fixes: 39447b386c84 ("perf: Enhance perf to allow for guest statistic collection from host") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20211111020738.2512932-2-seanjc@google.com
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369461ce |
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08-Dec-2021 |
Rob Herring <robh@kernel.org> |
x86: perf: Move RDPMC event flag to a common definition In preparation to enable user counter access on arm64 and to move some of the user access handling to perf core, create a common event flag for user counter access and convert x86 to use it. Since the architecture specific flags start at the LSB, starting at the MSB for common flags. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Borislav Petkov <bp@alien8.de> Cc: x86@kernel.org Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: linux-perf-users@vger.kernel.org Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20211208201124.310740-2-robh@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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8b8ff8cc |
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07-Sep-2021 |
Adrian Hunter <adrian.hunter@intel.com> |
perf/x86: Add new event for AUX output counter index PEBS-via-PT records contain a mask of applicable counters. To identify which event belongs to which counter, a side-band event is needed. Until now, there has been no side-band event, and consequently users were limited to using a single event. Add such a side-band event. Note the event is optimised to output only when the counter index changes for an event. That works only so long as all PEBS-via-PT events are scheduled together, which they are for a recording session because they are in a single group. Also no attribute bit is used to select the new event, so a new kernel is not compatible with older perf tools. The assumption being that PEBS-via-PT is sufficiently esoteric that users will not be troubled by this. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210907163903.11820-2-adrian.hunter@intel.com
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02d029a4 |
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29-Sep-2021 |
Anand K Mistry <amistry@google.com> |
perf/x86: Reset destroy callback on event init failure perf_init_event tries multiple init callbacks and does not reset the event state between tries. When x86_pmu_event_init runs, it unconditionally sets the destroy callback to hw_perf_event_destroy. On the next init attempt after x86_pmu_event_init, in perf_try_init_event, if the pmu's capabilities includes PERF_PMU_CAP_NO_EXCLUDE, the destroy callback will be run. However, if the next init didn't set the destroy callback, hw_perf_event_destroy will be run (since the callback wasn't reset). Looking at other pmu init functions, the common pattern is to only set the destroy callback on a successful init. Resetting the callback on failure tries to replicate that pattern. This was discovered after commit f11dd0d80555 ("perf/x86/amd/ibs: Extend PERF_PMU_CAP_NO_EXCLUDE to IBS Op") when the second (and only second) run of the perf tool after a reboot results in 0 samples being generated. The extra run of hw_perf_event_destroy results in active_events having an extra decrement on each perf run. The second run has active_events == 0 and every subsequent run has active_events < 0. When active_events == 0, the NMI handler will early-out and not record any samples. Signed-off-by: Anand K Mistry <amistry@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210929170405.1.I078b98ee7727f9ae9d6df8262bad7e325e40faf0@changeid
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4f32da76 |
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03-Aug-2021 |
Colin Ian King <colin.king@canonical.com> |
perf/x86: Remove unused assignment to pointer 'e' The pointer 'e' is being assigned a value that is never read, the assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210804115710.109608-1-colin.king@canonical.com
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f4b4b456 |
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29-Jul-2021 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix out of bound MSR access On Wed, Jul 28, 2021 at 12:49:43PM -0400, Vince Weaver wrote: > [32694.087403] unchecked MSR access error: WRMSR to 0x318 (tried to write 0x0000000000000000) at rIP: 0xffffffff8106f854 (native_write_msr+0x4/0x20) > [32694.101374] Call Trace: > [32694.103974] perf_clear_dirty_counters+0x86/0x100 The problem being that it doesn't filter out all fake counters, in specific the above (erroneously) tries to use FIXED_BTS. Limit the fixed counters indexes to the hardware supplied number. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Like Xu <likexu@tencent.com> Link: https://lkml.kernel.org/r/YQJxka3dxgdIdebG@hirez.programming.kicks-ass.net
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5471eea5 |
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14-Jun-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task The counter value of a perf task may leak to another RDPMC task. For example, a perf stat task as below is running on CPU 0. perf stat -e 'branches,cycles' -- taskset -c 0 ./workload In the meantime, an RDPMC task, which is also running on CPU 0, may read the GP counters periodically. (The RDPMC task creates a fixed event, but read four GP counters.) $./rdpmc_read_all_counters index 0x0 value 0x8001e5970f99 index 0x1 value 0x8005d750edb6 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x8002358e48a5 index 0x1 value 0x8006bd1e3bc9 index 0x2 value 0x0 index 0x3 value 0x0 It is a potential security issue. Once the attacker knows what the other thread is counting. The PerfMon counter can be used as a side-channel to attack cryptosystems. The counter value of the perf stat task leaks to the RDPMC task because perf never clears the counter when it's stopped. Three methods were considered to address the issue. - Unconditionally reset the counter in x86_pmu_del(). It can bring extra overhead even when there is no RDPMC task running. - Only reset the un-assigned dirty counters when the RDPMC task is scheduled in via sched_task(). It fails for the below case. Thread A Thread B clone(CLONE_THREAD) ---> set_affine(0) set_affine(1) while (!event-enabled) ; event = perf_event_open() mmap(event) ioctl(event, IOC_ENABLE); ---> RDPMC Counters are still leaked to the thread B. - Only reset the un-assigned dirty counters before updating the CR4.PCE bit. The method is implemented here. The dirty counter is a counter, on which the assigned event has been deleted, but the counter is not reset. To track the dirty counters, add a 'dirty' variable in the struct cpu_hw_events. The security issue can only be found with an RDPMC task. To enable the RDMPC, the CR4.PCE bit has to be updated. Add a perf_clear_dirty_counters() right before updating the CR4.PCE bit to clear the existing dirty counters. Only the current un-assigned dirty counters are reset, because the RDPMC assigned dirty counters will be updated soon. After applying the patch, $ ./rdpmc_read_all_counters index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 index 0x0 value 0x0 index 0x1 value 0x0 index 0x2 value 0x0 index 0x3 value 0x0 Performance The performance of a context switch only be impacted when there are two or more perf users and one of the users must be an RDPMC user. In other cases, there is no performance impact. The worst-case occurs when there are two users: the RDPMC user only uses one counter; while the other user uses all available counters. When the RDPMC task is scheduled in, all the counters, other than the RDPMC assigned one, have to be reset. Test results for the worst-case, using a modified lat_ctx as measured on an Ice Lake platform, which has 8 GP and 3 FP counters (ignoring SLOTS). lat_ctx -s 128K -N 1000 processes 2 Without the patch: The context switch time is 4.97 us With the patch: The context switch time is 5.16 us There is ~4% performance drop for the context switching time in the worst-case. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1623693582-187370-1-git-send-email-kan.liang@linux.intel.com
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488e13a4 |
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29-Apr-2021 |
Like Xu <like.xu@linux.intel.com> |
perf/x86/lbr: Remove cpuc->lbr_xsave allocation from atomic context If the kernel is compiled with the CONFIG_LOCKDEP option, the conditional might_sleep_if() deep in kmem_cache_alloc() will generate the following trace, and potentially cause a deadlock when another LBR event is added: [] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:196 [] Call Trace: [] kmem_cache_alloc+0x36/0x250 [] intel_pmu_lbr_add+0x152/0x170 [] x86_pmu_add+0x83/0xd0 Make it symmetric with the release_lbr_buffers() call and mirror the existing DS buffers. Fixes: c085fb8774 ("perf/x86/intel/lbr: Support XSAVES for arch LBR read") Signed-off-by: Like Xu <like.xu@linux.intel.com> [peterz: simplified] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lkml.kernel.org/r/20210430052247.3079672-2-like.xu@linux.intel.com
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32d35c4a |
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20-Apr-2021 |
Colin Ian King <colin.king@canonical.com> |
perf/x86: Allow for 8<num_fixed_counters<16 The 64 bit value read from MSR_ARCH_PERFMON_FIXED_CTR_CTRL is being bit-wise masked with the value (0x03 << i*4). However, the shifted value is evaluated using 32 bit arithmetic, so will UB when i > 8. Fix this by making 0x03 a ULL so that the shift is performed using 64 bit arithmetic. This makes the arithmetic internally consistent and preparers for the day when hardware provides 8<num_fixed_counters<16. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210420142907.382417-1-colin.king@canonical.com
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55bcf6ef |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf: Extend PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE Current Hardware events and Hardware cache events have special perf types, PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE. The two types don't pass the PMU type in the user interface. For a hybrid system, the perf subsystem doesn't know which PMU the events belong to. The first capable PMU will always be assigned to the events. The events never get a chance to run on the other capable PMUs. Extend the two types to become PMU aware types. The PMU type ID is stored at attr.config[63:32]. Add a new PMU capability, PERF_PMU_CAP_EXTENDED_HW_TYPE, to indicate a PMU which supports the extended PERF_TYPE_HARDWARE and PERF_TYPE_HW_CACHE. The PMU type is only required when searching a specific PMU. The PMU specific codes will only be interested in the 'real' config value, which is stored in the low 32 bit of the event->attr.config. Update the event->attr.config in the generic code, so the PMU specific codes don't need to calculate it separately. If a user specifies a PMU type, but the PMU doesn't support the extended type, error out. If an event cannot be initialized in a PMU specified by a user, error out immediately. Perf should not try to open it on other PMUs. The new PMU capability is only set for the X86 hybrid PMUs for now. Other architectures, e.g., ARM, may need it as well. The support on ARM may be implemented later separately. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618237865-33448-22-git-send-email-kan.liang@linux.intel.com
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3e9a8b21 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Support filter_match callback Implement filter_match callback for X86, which check whether an event is schedulable on the current CPU. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-20-git-send-email-kan.liang@linux.intel.com
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a9c81ccd |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Add structures for the attributes of Hybrid PMUs Hybrid PMUs have different events and formats. In theory, Hybrid PMU specific attributes should be maintained in the dedicated struct x86_hybrid_pmu, but it wastes space because the events and formats are similar among Hybrid PMUs. To reduce duplication, all hybrid PMUs will share a group of attributes in the following patch. To distinguish an attribute from different Hybrid PMUs, a PMU aware attribute structure is introduced. A PMU type is required for the attribute structure. The type is internal usage. It is not visible in the sysfs API. Hybrid PMUs may support the same event name, but with different event encoding, e.g., the mem-loads event on an Atom PMU has different event encoding from a Core PMU. It brings issue if two attributes are created for them. Current sysfs_update_group finds an attribute by searching the attr name (aka event name). If two attributes have the same event name, the first attribute will be replaced. To address the issue, only one attribute is created for the event. The event_str is extended and stores event encodings from all Hybrid PMUs. Each event encoding is divided by ";". The order of the event encodings must follow the order of the hybrid PMU index. The event_str is internal usage as well. When a user wants to show the attribute of a Hybrid PMU, only the corresponding part of the string is displayed. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-18-git-send-email-kan.liang@linux.intel.com
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d9977c43 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Register hybrid PMUs Different hybrid PMUs have different PMU capabilities and events. Perf should registers a dedicated PMU for each of them. To check the X86 event, perf has to go through all possible hybrid pmus. All the hybrid PMUs are registered at boot time. Before the registration, add intel_pmu_check_hybrid_pmus() to check and update the counters information, the event constraints, the extra registers and the unique capabilities for each hybrid PMUs. Postpone the display of the PMU information and HW check to CPU_STARTING, because the boot CPU is the only online CPU in the init_hw_perf_events(). Perf doesn't know the availability of the other PMUs. Perf should display the PMU information only if the counters of the PMU are available. One type of CPUs may be all offline. For this case, users can still observe the PMU in /sys/devices, but its CPU mask is 0. All hybrid PMUs have capability PERF_PMU_CAP_HETEROGENEOUS_CPUS. The PMU name for hybrid PMUs will be "cpu_XXX", which will be assigned later in a separated patch. The PMU type id for the core PMU is still PERF_TYPE_RAW. For the other hybrid PMUs, the PMU type id is not hard code. The event->cpu must be compatitable with the supported CPUs of the PMU. Add a check in the x86_pmu_event_init(). The events in a group must be from the same type of hybrid PMU. The fake cpuc used in the validation must be from the supported CPU of the event->pmu. Perf may not retrieve a valid core type from get_this_hybrid_cpu_type(). For example, ADL may have an alternative configuration. With that configuration, Perf cannot retrieve the core type from the CPUID leaf 0x1a. Add a platform specific get_hybrid_cpu_type(). If the generic way fails, invoke the platform specific get_hybrid_cpu_type(). Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618237865-33448-17-git-send-email-kan.liang@linux.intel.com
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e11c1a7e |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Factor out x86_pmu_show_pmu_cap The PMU capabilities are different among hybrid PMUs. Perf should dump the PMU capabilities information for each hybrid PMU. Factor out x86_pmu_show_pmu_cap() which shows the PMU capabilities information. The function will be reused later when registering a dedicated hybrid PMU. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-16-git-send-email-kan.liang@linux.intel.com
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b9856729 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Remove temporary pmu assignment in event_init The temporary pmu assignment in event_init is unnecessary. The assignment was introduced by commit 8113070d6639 ("perf_events: Add fast-path to the rescheduling code"). At that time, event->pmu is not assigned yet when initializing an event. The assignment is required. However, from commit 7e5b2a01d2ca ("perf: provide PMU when initing events"), the event->pmu is provided before event_init is invoked. The temporary pmu assignment in event_init should be removed. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-15-git-send-email-kan.liang@linux.intel.com
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183af736 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Hybrid PMU support for extra_regs Different hybrid PMU may have different extra registers, e.g. Core PMU may have offcore registers, frontend register and ldlat register. Atom core may only have offcore registers and ldlat register. Each hybrid PMU should use its own extra_regs. An Intel Hybrid system should always have extra registers. Unconditionally allocate shared_regs for Intel Hybrid system. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-11-git-send-email-kan.liang@linux.intel.com
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24ee38ff |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Hybrid PMU support for event constraints The events are different among hybrid PMUs. Each hybrid PMU should use its own event constraints. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-10-git-send-email-kan.liang@linux.intel.com
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0d18f2df |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Hybrid PMU support for hardware cache event The hardware cache events are different among hybrid PMUs. Each hybrid PMU should have its own hw cache event table. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618237865-33448-9-git-send-email-kan.liang@linux.intel.com
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d4b294bf |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Hybrid PMU support for counters The number of GP and fixed counters are different among hybrid PMUs. Each hybrid PMU should use its own counter related information. When handling a certain hybrid PMU, apply the number of counters from the corresponding hybrid PMU. When reserving the counters in the initialization of a new event, reserve all possible counters. The number of counter recored in the global x86_pmu is for the architecture counters which are available for all hybrid PMUs. KVM doesn't support the hybrid PMU yet. Return the number of the architecture counters for now. For the functions only available for the old platforms, e.g., intel_pmu_drain_pebs_nhm(), nothing is changed. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-7-git-send-email-kan.liang@linux.intel.com
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fc4b8fca |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Hybrid PMU support for intel_ctrl The intel_ctrl is the counter mask of a PMU. The PMU counter information may be different among hybrid PMUs, each hybrid PMU should use its own intel_ctrl to check and access the counters. When handling a certain hybrid PMU, apply the intel_ctrl from the corresponding hybrid PMU. When checking the HW existence, apply the PMU and number of counters from the corresponding hybrid PMU as well. Perf will check the HW existence for each Hybrid PMU before registration. Expose the check_hw_exists() for a later patch. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Link: https://lkml.kernel.org/r/1618237865-33448-6-git-send-email-kan.liang@linux.intel.com
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d0946a88 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Hybrid PMU support for perf capabilities Some platforms, e.g. Alder Lake, have hybrid architecture. Although most PMU capabilities are the same, there are still some unique PMU capabilities for different hybrid PMUs. Perf should register a dedicated pmu for each hybrid PMU. Add a new struct x86_hybrid_pmu, which saves the dedicated pmu and capabilities for each hybrid PMU. The architecture MSR, MSR_IA32_PERF_CAPABILITIES, only indicates the architecture features which are available on all hybrid PMUs. The architecture features are stored in the global x86_pmu.intel_cap. For Alder Lake, the model-specific features are perf metrics and PEBS-via-PT. The corresponding bits of the global x86_pmu.intel_cap should be 0 for these two features. Perf should not use the global intel_cap to check the features on a hybrid system. Add a dedicated intel_cap in the x86_hybrid_pmu to store the model-specific capabilities. Use the dedicated intel_cap to replace the global intel_cap for thse two features. The dedicated intel_cap will be set in the following "Add Alder Lake Hybrid support" patch. Add is_hybrid() to distinguish a hybrid system. ADL may have an alternative configuration. With that configuration, the X86_FEATURE_HYBRID_CPU is not set. Perf cannot rely on the feature bit. Add a new static_key_false, perf_is_hybrid, to indicate a hybrid system. It will be assigned in the following "Add Alder Lake Hybrid support" patch as well. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618237865-33448-5-git-send-email-kan.liang@linux.intel.com
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61e76d53 |
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12-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Track pmu in per-CPU cpu_hw_events Some platforms, e.g. Alder Lake, have hybrid architecture. In the same package, there may be more than one type of CPU. The PMU capabilities are different among different types of CPU. Perf will register a dedicated PMU for each type of CPU. Add a 'pmu' variable in the struct cpu_hw_events to track the dedicated PMU of the current CPU. Current x86_get_pmu() use the global 'pmu', which will be broken on a hybrid platform. Modify it to apply the 'pmu' of the specific CPU. Initialize the per-CPU 'pmu' variable with the global 'pmu'. There is nothing changed for the non-hybrid platforms. The is_x86_event() will be updated in the later patch ("perf/x86: Register hybrid PMUs") for hybrid platforms. For the non-hybrid platforms, nothing is changed here. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618237865-33448-4-git-send-email-kan.liang@linux.intel.com
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46ade474 |
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14-Apr-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Move cpuc->running into P4 specific code The 'running' variable is only used in the P4 PMU. Current perf sets the variable in the critical function x86_pmu_start(), which wastes cycles for everybody not running on P4. Move cpuc->running into the P4 specific p4_pmu_enable_event(). Add a static per-CPU 'p4_running' variable to replace the 'running' variable in the struct cpu_hw_events. Saves space for the generic structure. The p4_pmu_enable_all() also invokes the p4_pmu_enable_event(), but it should not set cpuc->running. Factor out __p4_pmu_enable_event() for p4_pmu_enable_all(). Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1618410990-21383-1-git-send-email-kan.liang@linux.intel.com
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d9f6e12f |
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18-Mar-2021 |
Ingo Molnar <mingo@kernel.org> |
x86: Fix various typos in comments Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
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c8e2fe13 |
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09-Mar-2021 |
Sean Christopherson <seanjc@google.com> |
x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case Initialize x86_pmu.guest_get_msrs to return 0/NULL to handle the "nop" case. Patching in perf_guest_get_msrs_nop() during setup does not work if there is no PMU, as setup bails before updating the static calls, leaving x86_pmu.guest_get_msrs NULL and thus a complete nop. Ultimately, this causes VMX abort on VM-Exit due to KVM putting random garbage from the stack into the MSR load list. Add a comment in KVM to note that nr_msrs is valid if and only if the return value is non-NULL. Fixes: abd562df94d1 ("x86/perf: Use static_call for x86_pmu.guest_get_msrs") Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: syzbot+cce9ef2dd25246f815ee@syzkaller.appspotmail.com Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210309171019.1125243-1-seanjc@google.com
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32451614 |
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28-Jan-2021 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Support CPUID 10.ECX to disable fixed counters With Architectural Performance Monitoring Version 5, CPUID 10.ECX cpu leaf indicates the fixed counter enumeration. This extends the previous count to a bitmap which allows disabling even lower fixed counters. It could be used by a Hypervisor. The existing intel_ctrl variable is used to remember the bitmask of the counters. All code that reads all counters is fixed to check this extra bitmask. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Originally-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1611873611-156687-6-git-send-email-kan.liang@linux.intel.com
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abd562df |
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25-Jan-2021 |
Like Xu <like.xu@linux.intel.com> |
x86/perf: Use static_call for x86_pmu.guest_get_msrs Clean up that CONFIG_RETPOLINE crud and replace the indirect call x86_pmu.guest_get_msrs with static_call(). Reported-by: kernel test robot <lkp@intel.com> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Like Xu <like.xu@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210125121458.181635-1-like.xu@linux.intel.com
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b6459575 |
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19-Nov-2020 |
Gustavo A. R. Silva <gustavoars@kernel.org> |
perf/x86: Fix fall-through warnings for Clang In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a fallthrough pseudo-keyword as a replacement for a /* fall through */ comment, instead of letting the code fall through to the next case. Notice that Clang doesn't recognize /* fall through */ comments as implicit fall-through markings. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://github.com/KSPP/linux/issues/115
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375d4bfd |
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03-Oct-2020 |
Gabriel Krisman Bertazi <krisman@collabora.com> |
perf/x86: Avoid TIF_IA32 when checking 64bit mode In preparation to remove TIF_IA32, stop using it in perf events code. Tested by running perf on 32-bit, 64-bit and x32 applications. Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20201004032536.1229030-2-krisman@collabora.com
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3dbde695 |
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05-Oct-2020 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix n_metric for cancelled txn When a group that has TopDown members is failed to be scheduled, any later TopDown groups will not return valid values. Here is an example. A background perf that occupies all the GP counters and the fixed counter 1. $perf stat -e "{cycles,cycles,cycles,cycles,cycles,cycles,cycles, cycles,cycles}:D" -a A user monitors a TopDown group. It works well, because the fixed counter 3 and the PERF_METRICS are available. $perf stat -x, --topdown -- ./workload retiring,bad speculation,frontend bound,backend bound, 18.0,16.1,40.4,25.5, Then the user tries to monitor a group that has TopDown members. Because of the cycles event, the group is failed to be scheduled. $perf stat -x, -e '{slots,topdown-retiring,topdown-be-bound, topdown-fe-bound,topdown-bad-spec,cycles}' -- ./workload <not counted>,,slots,0,0.00,, <not counted>,,topdown-retiring,0,0.00,, <not counted>,,topdown-be-bound,0,0.00,, <not counted>,,topdown-fe-bound,0,0.00,, <not counted>,,topdown-bad-spec,0,0.00,, <not counted>,,cycles,0,0.00,, The user tries to monitor a TopDown group again. It doesn't work anymore. $perf stat -x, --topdown -- ./workload ,,,,, In a txn, cancel_txn() is to truncate the event_list for a canceled group and update the number of events added in this transaction. However, the number of TopDown events added in this transaction is not updated. The kernel will probably fail to add new Topdown events. Fixes: 7b2c05a15d29 ("perf/x86/intel: Generic support for hardware TopDown metrics") Reported-by: Andi Kleen <ak@linux.intel.com> Reported-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lkml.kernel.org/r/20201005082611.GH2628@hirez.programming.kicks-ass.net
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871a93b0 |
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05-Oct-2020 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix n_pair for cancelled txn Kan reported that n_metric gets corrupted for cancelled transactions; a similar issue exists for n_pair for AMD's Large Increment thing. The problem was confirmed and confirmed fixed by Kim using: sudo perf stat -e "{cycles,cycles,cycles,cycles}:D" -a sleep 10 & # should succeed: sudo perf stat -e "{fp_ret_sse_avx_ops.all}:D" -a workload # should fail: sudo perf stat -e "{fp_ret_sse_avx_ops.all,fp_ret_sse_avx_ops.all,cycles}:D" -a workload # previously failed, now succeeds with this patch: sudo perf stat -e "{fp_ret_sse_avx_ops.all}:D" -a workload Fixes: 5738891229a2 ("perf/x86/amd: Add support for Large Increment per Cycle Events") Reported-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Kim Phillips <kim.phillips@amd.com> Link: https://lkml.kernel.org/r/20201005082516.GG2628@hirez.programming.kicks-ass.net
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26e52558 |
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08-Sep-2020 |
Kim Phillips <kim.phillips@amd.com> |
perf/x86/amd: Fix sampling Large Increment per Cycle events Commit 5738891229a2 ("perf/x86/amd: Add support for Large Increment per Cycle Events") mistakenly zeroes the upper 16 bits of the count in set_period(). That's fine for counting with perf stat, but not sampling with perf record when only Large Increment events are being sampled. To enable sampling, we sign extend the upper 16 bits of the merged counter pair as described in the Family 17h PPRs: "Software wanting to preload a value to a merged counter pair writes the high-order 16-bit value to the low-order 16 bits of the odd counter and then writes the low-order 48-bit value to the even counter. Reading the even counter of the merged counter pair returns the full 64-bit value." Fixes: 5738891229a2 ("perf/x86/amd: Add support for Large Increment per Cycle Events") Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
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7c9903c9 |
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18-Aug-2020 |
Peter Zijlstra <peterz@infradead.org> |
x86/perf, static_call: Optimize x86_pmu methods Replace many of the indirect calls with static_call(). The average PMI time, as measured by perf_sample_event_took()*: PRE: 3283.03 [ns] POST: 3145.12 [ns] Which is a ~138 [ns] win per PMI, or a ~4.2% decrease. [*] on an IVB-EP, using: 'perf record -a -e cycles -- make O=defconfig-build/ -j80' Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20200818135805.338001015@infradead.org
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2cb5383b |
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23-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Support per-thread RDPMC TopDown metrics Starts from Ice Lake, the TopDown metrics are directly available as fixed counters and do not require generic counters. Also, the TopDown metrics can be collected per thread. Extend the RDPMC usage to support per-thread TopDown metrics. The RDPMC index of the PERF_METRICS will be output if RDPMC users ask for the RDPMC index of the metrics events. To support per thread RDPMC TopDown, the metrics and slots counters have to be saved/restored during the context switching. The last_period and period_left are not used in the counting mode. Use the fields for saved_metric and saved_slots. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200723171117.9918-12-kan.liang@linux.intel.com
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0e2e45e2 |
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23-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Add a macro for RDPMC offset of fixed counters The RDPMC base offset of fixed counters is hard-code. Use a meaningful name to replace the magic number to improve the readability of the code. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200723171117.9918-10-kan.liang@linux.intel.com
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7b2c05a1 |
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23-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Generic support for hardware TopDown metrics Intro ===== The TopDown Microarchitecture Analysis (TMA) Method is a structured analysis methodology to identify critical performance bottlenecks in out-of-order processors. Current perf has supported the method. The method works well, but there is one problem. To collect the TopDown events, several GP counters have to be used. If a user wants to collect other events at the same time, the multiplexing probably be triggered, which impacts the accuracy. To free up the scarce GP counters, the hardware TopDown metrics feature is introduced from Ice Lake. The hardware implements an additional "metrics" register and a new Fixed Counter 3 that measures pipeline "slots". The TopDown events can be calculated from them instead. Events ====== The level 1 TopDown has four metrics. There is no event-code assigned to the TopDown metrics. Four metric events are exported as separate perf events, which map to the internal "metrics" counter register. Those events do not exist in hardware, but can be allocated by the scheduler. For the event mapping, a special 0x00 event code is used, which is reserved for fake events. The metric events start from umask 0x10. When setting up the metric events, they point to the Fixed Counter 3. They have to be specially handled. - Add the update_topdown_event() callback to read the additional metrics MSR and generate the metrics. - Add the set_topdown_event_period() callback to initialize metrics MSR and the fixed counter 3. - Add a variable n_metric_event to track the number of the accepted metrics events. The sharing between multiple users of the same metric without multiplexing is not allowed. - Only enable/disable the fixed counter 3 when there are no other active TopDown events, which avoid the unnecessary writing of the fixed control register. - Disable the PMU when reading the metrics event. The metrics MSR and the fixed counter 3 are read separately. The values may be modified by an NMI. All four metric events don't support sampling. Since they will be handled specially for event update, a flag PERF_X86_EVENT_TOPDOWN is introduced to indicate this case. The slots event can support both sampling and counting. For counting, the flag is also applied. For sampling, it will be handled normally as other normal events. Groups ====== The slots event is required in a Topdown group. To avoid reading the METRICS register multiple times, the metrics and slots value can only be updated by slots event in a group. All active slots and metrics events will be updated one time. Therefore, the slots event must be before any metric events in a Topdown group. NMI ====== The METRICS related register may be overflow. The bit 48 of the STATUS register will be set. If so, PERF_METRICS and Fixed counter 3 are required to be reset. The patch also update all active slots and metrics events in the NMI handler. The update_topdown_event() has to read two registers separately. The values may be modified by an NMI. PMU has to be disabled before calling the function. RDPMC ====== RDPMC is temporarily disabled. A later patch will enable it. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200723171117.9918-9-kan.liang@linux.intel.com
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75608cb0 |
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23-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Use event_base_rdpmc for the RDPMC userspace support The RDPMC index is always re-calculated for the RDPMC userspace support, which is unnecessary. The RDPMC index value is stored in the variable event_base_rdpmc for the kernel usage, which can be used for RDPMC userspace support as well. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200723171117.9918-2-kan.liang@linux.intel.com
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c085fb87 |
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03-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel/lbr: Support XSAVES for arch LBR read Reading LBR registers in a perf NMI handler for a non-PEBS event causes a high overhead because the number of LBR registers is huge. To reduce the overhead, the XSAVES instruction should be used to replace the LBR registers' reading method. The XSAVES buffer used for LBR read has to be per-CPU because the NMI handler invoked the lbr_read(). The existing task_ctx_data buffer cannot be used which is per-task and only be allocated for the LBR call stack mode. A new lbr_xsave pointer is introduced in the cpu_hw_events as an XSAVES buffer for LBR read. The XSAVES buffer should be allocated only when LBR is used by a non-PEBS event on the CPU because the total size of the lbr_xsave is not small (~1.4KB). The XSAVES buffer is allocated when a non-PEBS event is added, but it is lazily released in x86_release_hardware() when perf releases the entire PMU hardware resource, because perf may frequently schedule the event, e.g. high context switch. The lazy release method reduces the overhead of frequently allocate/free the buffer. If the lbr_xsave fails to be allocated, roll back to normal Arch LBR lbr_read(). Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Link: https://lkml.kernel.org/r/1593780569-62993-24-git-send-email-kan.liang@linux.intel.com
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5a09928d |
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03-Jul-2020 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Remove task_ctx_size A new kmem_cache method has replaced the kzalloc() to allocate the PMU specific data. The task_ctx_size is not required anymore. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1593780569-62993-19-git-send-email-kan.liang@linux.intel.com
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#
097e4311 |
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13-Jun-2020 |
Like Xu <like.xu@linux.intel.com> |
perf/x86: Add constraint to create guest LBR event without hw counter The hypervisor may request the perf subsystem to schedule a time window to directly access the LBR records msrs for its own use. Normally, it would create a guest LBR event with callstack mode enabled, which is scheduled along with other ordinary LBR events on the host but in an exclusive way. To avoid wasting a counter for the guest LBR event, the perf tracks its hw->idx via INTEL_PMC_IDX_FIXED_VLBR and assigns it with a fake VLBR counter with the help of new vlbr_constraint. As with the BTS event, there is actually no hardware counter assigned for the guest LBR event. Signed-off-by: Like Xu <like.xu@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200514083054.62538-5-like.xu@linux.intel.com
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#
027440b5 |
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13-Jun-2020 |
Like Xu <like.xu@linux.intel.com> |
perf/x86/core: Refactor hw->idx checks and cleanup For intel_pmu_en/disable_event(), reorder the branches checks for hw->idx and make them sorted by probability: gp,fixed,bts,others. Clean up the x86_assign_hw_event() by converting multiple if-else statements to a switch statement. To skip x86_perf_event_update() and x86_perf_event_set_period(), it's generic to replace "idx == INTEL_PMC_IDX_FIXED_BTS" check with '!hwc->event_base' because that should be 0 for all non-gp/fixed cases. Wrap related bit operations into intel_set/clear_masks() and make the main path more cleaner and readable. No functional changes. Signed-off-by: Like Xu <like.xu@linux.intel.com> Original-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200613080958.132489-3-like.xu@linux.intel.com
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c1e8d7c6 |
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08-Jun-2020 |
Michel Lespinasse <walken@google.com> |
mmap locking API: convert mmap_sem comments Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
42fc5414 |
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08-Jun-2020 |
Michel Lespinasse <walken@google.com> |
mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked() Add new APIs to assert that mmap_sem is held. Using this instead of rwsem_is_locked and lockdep_assert_held[_write] makes the assertions more tolerant of future changes to the lock type. Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-10-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3a4ac121 |
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12-Apr-2020 |
CodyYao-oc <CodyYao-oc@zhaoxin.com> |
x86/perf: Add hardware performance events support for Zhaoxin CPU. Zhaoxin CPU has provided facilities for monitoring performance via PMU (Performance Monitor Unit), but the functionality is unused so far. Therefore, add support for zhaoxin pmu to make performance related hardware events available. The PMU is mostly an Intel Architectural PerfMon-v2 with a novel errata for the ZXC line. It supports the following events: ----------------------------------------------------------------------------------------------------------------------------------- Event | Event | Umask | Description | Select | | ----------------------------------------------------------------------------------------------------------------------------------- cpu-cycles | 82h | 00h | unhalt core clock instructions | 00h | 00h | number of instructions at retirement. cache-references | 15h | 05h | number of fillq pushs at the current cycle. cache-misses | 1ah | 05h | number of l2 miss pushed by fillq. branch-instructions | 28h | 00h | counts the number of branch instructions retired. branch-misses | 29h | 00h | mispredicted branch instructions at retirement. bus-cycles | 83h | 00h | unhalt bus clock stalled-cycles-frontend | 01h | 01h | Increments each cycle the # of Uops issued by the RAT to RS. stalled-cycles-backend | 0fh | 04h | RS0/1/2/3/45 empty L1-dcache-loads | 68h | 05h | number of retire/commit load. L1-dcache-load-misses | 4bh | 05h | retired load uops whose data source followed an L1 miss. L1-dcache-stores | 69h | 06h | number of retire/commit Store,no LEA L1-dcache-store-misses | 62h | 05h | cache lines in M state evicted out of L1D due to Snoop HitM or dirty line replacement. L1-icache-loads | 00h | 03h | number of l1i cache access for valid normal fetch,including un-cacheable access. L1-icache-load-misses | 01h | 03h | number of l1i cache miss for valid normal fetch,including un-cacheable miss. L1-icache-prefetches | 0ah | 03h | number of prefetch. L1-icache-prefetch-misses | 0bh | 03h | number of prefetch miss. dTLB-loads | 68h | 05h | number of retire/commit load dTLB-load-misses | 2ch | 05h | number of load operations miss all level tlbs and cause a tablewalk. dTLB-stores | 69h | 06h | number of retire/commit Store,no LEA dTLB-store-misses | 30h | 05h | number of store operations miss all level tlbs and cause a tablewalk. dTLB-prefetches | 64h | 05h | number of hardware pte prefetch requests dispatched out of the prefetch FIFO. dTLB-prefetch-misses | 65h | 05h | number of hardware pte prefetch requests miss the l1d data cache. iTLB-load | 00h | 00h | actually counter instructions. iTLB-load-misses | 34h | 05h | number of code operations miss all level tlbs and cause a tablewalk. ----------------------------------------------------------------------------------------------------------------------------------- Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: CodyYao-oc <CodyYao-oc@zhaoxin.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/1586747669-4827-1-git-send-email-CodyYao-oc@zhaoxin.com
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#
cb2a0235 |
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21-Apr-2020 |
Thomas Gleixner <tglx@linutronix.de> |
x86/cr4: Sanitize CR4.PCE update load_mm_cr4_irqsoff() is really a strange name for a function which has only one purpose: Update the CR4.PCE bit depending on the perf state. Rename it to update_cr4_pce_mm(), move it into the tlb code and provide a function which can be invoked by the perf smp function calls. Another step to remove exposure of cpu_tlbstate. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200421092559.049499158@linutronix.de
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#
c8e3dd86 |
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15-Feb-2020 |
Al Viro <viro@zeniv.linux.org.uk> |
x86 user stack frame reads: switch to explicit __get_user() rather than relying upon the magic in raw_copy_from_user() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
57388912 |
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13-Nov-2019 |
Kim Phillips <kim.phillips@amd.com> |
perf/x86/amd: Add support for Large Increment per Cycle Events Description of hardware operation --------------------------------- The core AMD PMU has a 4-bit wide per-cycle increment for each performance monitor counter. That works for most events, but now with AMD Family 17h and above processors, some events can occur more than 15 times in a cycle. Those events are called "Large Increment per Cycle" events. In order to count these events, two adjacent h/w PMCs get their count signals merged to form 8 bits per cycle total. In addition, the PERF_CTR count registers are merged to be able to count up to 64 bits. Normally, events like instructions retired, get programmed on a single counter like so: PERF_CTL0 (MSR 0xc0010200) 0x000000000053ff0c # event 0x0c, umask 0xff PERF_CTR0 (MSR 0xc0010201) 0x0000800000000001 # r/w 48-bit count The next counter at MSRs 0xc0010202-3 remains unused, or can be used independently to count something else. When counting Large Increment per Cycle events, such as FLOPs, however, we now have to reserve the next counter and program the PERF_CTL (config) register with the Merge event (0xFFF), like so: PERF_CTL0 (msr 0xc0010200) 0x000000000053ff03 # FLOPs event, umask 0xff PERF_CTR0 (msr 0xc0010201) 0x0000800000000001 # rd 64-bit cnt, wr lo 48b PERF_CTL1 (msr 0xc0010202) 0x0000000f004000ff # Merge event, enable bit PERF_CTR1 (msr 0xc0010203) 0x0000000000000000 # wr hi 16-bits count The count is widened from the normal 48-bits to 64 bits by having the second counter carry the higher 16 bits of the count in its lower 16 bits of its counter register. The odd counter, e.g., PERF_CTL1, is programmed with the enabled Merge event before the even counter, PERF_CTL0. The Large Increment feature is available starting with Family 17h. For more details, search any Family 17h PPR for the "Large Increment per Cycle Events" section, e.g., section 2.1.15.3 on p. 173 in this version: https://www.amd.com/system/files/TechDocs/56176_ppr_Family_17h_Model_71h_B0_pub_Rev_3.06.zip Description of software operation --------------------------------- The following steps are taken in order to support reserving and enabling the extra counter for Large Increment per Cycle events: 1. In the main x86 scheduler, we reduce the number of available counters by the number of Large Increment per Cycle events being scheduled, tracked by a new cpuc variable 'n_pair' and a new amd_put_event_constraints_f17h(). This improves the counter scheduler success rate. 2. In perf_assign_events(), if a counter is assigned to a Large Increment event, we increment the current counter variable, so the counter used for the Merge event is removed from assignment consideration by upcoming event assignments. 3. In find_counter(), if a counter has been found for the Large Increment event, we set the next counter as used, to prevent other events from using it. 4. We perform steps 2 & 3 also in the x86 scheduler fastpath, i.e., we add Merge event accounting to the existing used_mask logic. 5. Finally, we add on the programming of Merge event to the neighbouring PMC counters in the counter enable/disable{_all} code paths. Currently, software does not support a single PMU with mixed 48- and 64-bit counting, so Large increment event counts are limited to 48 bits. In set_period, we zero-out the upper 16 bits of the count, so the hardware doesn't copy them to the even counter's higher bits. Simple invocation example showing counting 8 FLOPs per 256-bit/%ymm vaddps instruction executed in a loop 100 million times: perf stat -e cpu/fp_ret_sse_avx_ops.all/,cpu/instructions/ <workload> Performance counter stats for '<workload>': 800,000,000 cpu/fp_ret_sse_avx_ops.all/u 300,042,101 cpu/instructions/u Prior to this patch, the reported SSE/AVX FLOPs retired count would be wrong. [peterz: lots of renames and edits to the code] Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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#
92ca7da4 |
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09-Dec-2019 |
Alexander Shishkin <alexander.shishkin@linux.intel.com> |
perf/x86/intel: Fix PT PMI handling Commit: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") skips the PT/LBR exclusivity check on CPUs where PT and LBRs coexist, but also inadvertently skips the active_events bump for PT in that case, which is a bug. If there aren't any hardware events at the same time as PT, the PMI handler will ignore PT PMIs, as active_events reads zero in that case, resulting in the "Uhhuh" spurious NMI warning and PT data loss. Fix this by always increasing active_events for PT events. Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") Reported-by: Vitaly Slobodskoy <vitaly.slobodskoy@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lkml.kernel.org/r/20191210105101.77210-1-alexander.shishkin@linux.intel.com
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#
1e69a0ef |
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05-Dec-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix potential out-of-bounds access UBSAN reported out-of-bound accesses for x86_pmu.event_map(), it's arguments should be < x86_pmu.max_events. Make sure all users observe this constraint. Reported-by: Meelis Roos <mroos@linux.ee> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Meelis Roos <mroos@linux.ee>
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#
405b4537 |
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24-Nov-2019 |
Anthony Steinhauser <asteinhauser@google.com> |
perf/x86: Implement immediate enforcement of /sys/devices/cpu/rdpmc value of 0 When you successfully write 0 to /sys/devices/cpu/rdpmc, the RDPMC instruction should be disabled unconditionally and immediately (after you close the SYSFS file) by the documentation. Instead, in the current implementation the PMU must be reloaded which happens only eventually some time in the future. Only after that the RDPMC instruction becomes disabled (on ring 3) on the respective core. This change makes the treatment of the 0 value as blocking and as unconditional as the current treatment of the 2 value, only the CR4.PCE bit is naturally set to false instead of true. Signed-off-by: Anthony Steinhauser <asteinhauser@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Link: https://lkml.kernel.org/r/20191125054838.137615-1-asteinhauser@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
a4439970 |
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23-Oct-2019 |
Alexey Budankov <alexey.budankov@linux.intel.com> |
perf/x86: Install platform specific ->swap_task_ctx() adapter Bridge perf core and x86 swap_task_ctx() method calls. Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Song Liu <songliubraving@fb.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/b157e97d-32c3-aeaf-13ba-47350c677906@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
42880f72 |
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06-Aug-2019 |
Alexander Shishkin <alexander.shishkin@linux.intel.com> |
perf/x86/intel: Support PEBS output to PT If PEBS declares ability to output its data to Intel PT stream, use the aux_output attribute bit to enable PEBS data output to PT. This requires a PT event to be present and scheduled in the same context. Unlike the DS area, the kernel does not extract PEBS records from the PT stream to generate corresponding records in the perf stream, because that would require real time in-kernel PT decoding, which is not feasible. The PMI, however, can still be used. The output setting is per-CPU, so all PEBS events must be either writing to PT or to the DS area, therefore, in case of conflict, the conflicting event will fail to schedule, allowing the rotation logic to alternate between the PEBS->PT and PEBS->DS events. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: kan.liang@linux.intel.com Link: https://lkml.kernel.org/r/20190806084606.4021-3-alexander.shishkin@linux.intel.com
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#
77d76032 |
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16-Aug-2019 |
Su Yanjun <suyj.fnst@cn.fujitsu.com> |
perf/x86: Fix typo in comment No functional change. Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1565945001-4413-1-git-send-email-suyj.fnst@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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21e450d2 |
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18-Jun-2019 |
Jan Kiszka <jan.kiszka@siemens.com> |
x86/mm: Avoid redundant interrupt disable in load_mm_cr4() load_mm_cr4() is always called with interrupts disabled from: - switch_mm_irqs_off() - refresh_pce(), which is a on_each_cpu() callback Thus, disabling interrupts in cr4_set/clear_bits() is redundant. Implement cr4_set/clear_bits_irqsoff() helpers, rename load_mm_cr4() to load_mm_cr4_irqsoff() and use the new helpers. The new helpers do not need a lockdep assert as __cr4_set() has one already. The renaming in combination with the checks in __cr4_set() ensure that any changes in the boundary conditions at the call sites will be detected. [ tglx: Massaged change log ] Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/0fbbcb64-5f26-4ffb-1bb9-4f5f48426893@siemens.com
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#
83f44ae0 |
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26-Jun-2019 |
Song Liu <songliubraving@fb.com> |
perf/x86: Always store regs->ip in perf_callchain_kernel() The stacktrace_map_raw_tp BPF selftest is failing because the RIP saved by perf_arch_fetch_caller_regs() isn't getting saved by perf_callchain_kernel(). This was broken by the following commit: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER") With that change, when starting with non-HW regs, the unwinder starts with the current stack frame and unwinds until it passes up the frame which called perf_arch_fetch_caller_regs(). So regs->ip needs to be saved deliberately. Fixes: d15d356887e7 ("perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER") Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kairui Song <kasong@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/3975a298fa52b506fea32666d8ff6a13467eee6d.1561595111.git.jpoimboe@redhat.com
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#
cd6b984f |
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28-May-2019 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Remove pmu->pebs_no_xmm_regs We don't need pmu->pebs_no_xmm_regs anymore, the capabilities PERF_PMU_CAP_EXTENDED_REGS can be used to check if XMM registers collection is supported. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/1559081314-9714-4-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
dce86ac7 |
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28-May-2019 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Clean up PEBS_XMM_REGS Use generic macro PERF_REG_EXTENDED_MASK to replace PEBS_XMM_REGS to avoid duplication. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/1559081314-9714-3-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
9ffbe8ac |
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31-May-2019 |
Nikolay Borisov <nborisov@suse.com> |
locking/lockdep: Rename lockdep_assert_held_exclusive() -> lockdep_assert_held_write() All callers of lockdep_assert_held_exclusive() use it to verify the correct locking state of either a semaphore (ldisc_sem in tty, mmap_sem for perf events, i_rwsem of inode for dax) or rwlock by apparmor. Thus it makes sense to rename _exclusive to _write since that's the semantics callers care. Additionally there is already lockdep_assert_held_read(), which this new naming is more consistent with. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190531100651.3969-1-nborisov@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
6a9f4efe |
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12-May-2019 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86: Use update attribute groups for default attributes Using the new pmu::update_attrs attribute group for default attributes - freeze_on_smi, allow_tsx_force_abort. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-10-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
1f157286 |
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12-May-2019 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86: Use update attribute groups for caps Using the new pmu::update_attrs attribute group for "caps" directory. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-7-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
3d567273 |
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12-May-2019 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86: Add is_visible attribute_group callback for base events We dont need to pre-filter out unsupported base events, we can just use its group's is_visible function to do this. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-6-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
baa0c833 |
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12-May-2019 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86: Use the new pmu::update_attrs attribute group Using the new pmu::update_attrs attribute group to create detected events for x86_pmu. Moving the topdown/memory/tsx attributes to separate attribute groups with specific is_visible functions. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-5-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
21b0dbc5 |
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12-May-2019 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86: Get rid of x86_pmu::event_attrs Nobody is using that. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190512155518.21468-4-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d15d3568 |
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22-Apr-2019 |
Kairui Song <kasong@redhat.com> |
perf/x86: Make perf callchains work without CONFIG_FRAME_POINTER Currently perf callchain doesn't work well with ORC unwinder when sampling from trace point. We'll get useless in kernel callchain like this: perf 6429 [000] 22.498450: kmem:mm_page_alloc: page=0x176a17 pfn=1534487 order=0 migratetype=0 gfp_flags=GFP_KERNEL ffffffffbe23e32e __alloc_pages_nodemask+0x22e (/lib/modules/5.1.0-rc3+/build/vmlinux) 7efdf7f7d3e8 __poll+0x18 (/usr/lib64/libc-2.28.so) 5651468729c1 [unknown] (/usr/bin/perf) 5651467ee82a main+0x69a (/usr/bin/perf) 7efdf7eaf413 __libc_start_main+0xf3 (/usr/lib64/libc-2.28.so) 5541f689495641d7 [unknown] ([unknown]) The root cause is that, for trace point events, it doesn't provide a real snapshot of the hardware registers. Instead perf tries to get required caller's registers and compose a fake register snapshot which suppose to contain enough information for start a unwinding. However without CONFIG_FRAME_POINTER, if failed to get caller's BP as the frame pointer, so current frame pointer is returned instead. We get a invalid register combination which confuse the unwinder, and end the stacktrace early. So in such case just don't try dump BP, and let the unwinder start directly when the register is not a real snapshot. Use SP as the skip mark, unwinder will skip all the frames until it meet the frame of the trace point caller. Tested with frame pointer unwinder and ORC unwinder, this makes perf callchain get the full kernel space stacktrace again like this: perf 6503 [000] 1567.570191: kmem:mm_page_alloc: page=0x16c904 pfn=1493252 order=0 migratetype=0 gfp_flags=GFP_KERNEL ffffffffb523e2ae __alloc_pages_nodemask+0x22e (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb52383bd __get_free_pages+0xd (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb52fd28a __pollwait+0x8a (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb521426f perf_poll+0x2f (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb52fe3e2 do_sys_poll+0x252 (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb52ff027 __x64_sys_poll+0x37 (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb500418b do_syscall_64+0x5b (/lib/modules/5.1.0-rc3+/build/vmlinux) ffffffffb5a0008c entry_SYSCALL_64_after_hwframe+0x44 (/lib/modules/5.1.0-rc3+/build/vmlinux) 7f71e92d03e8 __poll+0x18 (/usr/lib64/libc-2.28.so) 55a22960d9c1 [unknown] (/usr/bin/perf) 55a22958982a main+0x69a (/usr/bin/perf) 7f71e9202413 __libc_start_main+0xf3 (/usr/lib64/libc-2.28.so) 5541f689495641d7 [unknown] ([unknown]) Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Kairui Song <kasong@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Young <dyoung@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190422162652.15483-1-kasong@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
878068ea |
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02-Apr-2019 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Support outputting XMM registers Starting from Icelake, XMM registers can be collected in PEBS record. But current code only output the pt_regs. Add a new struct x86_perf_regs for both pt_regs and xmm_regs. The xmm_regs will be used later to keep a pointer to PEBS record which has XMM information. XMM registers are 128 bit. To simplify the code, they are handled like two different registers, which means setting two bits in the register bitmap. This also allows only sampling the lower 64bit bits in XMM. The index of XMM registers starts from 32. There are 16 XMM registers. So all reserved space for regs are used. Remove REG_RESERVED. Add PERF_REG_X86_XMM_MAX, which stands for the max number of all x86 regs including both GPRs and XMM. Add REG_NOSUPPORT for 32bit to exclude unsupported registers. Previous platforms can not collect XMM information in PEBS record. Adding pebs_no_xmm_regs to indicate the unsupported platforms. The common code still validates the supported registers. However, it cannot check model specific registers, e.g. XMM. Add extra check in x86_pmu_hw_config() to reject invalid config of regs_user and regs_intr. The regs_user never supports XMM collection. The regs_intr only supports XMM collection when sampling PEBS event on icelake and later platforms. Originally-by: Andi Kleen <ak@linux.intel.com> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: https://lkml.kernel.org/r/20190402194509.2832-3-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
f447e4eb |
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08-Apr-2019 |
Stephane Eranian <eranian@google.com> |
perf/x86/intel: Force resched when TFA sysctl is modified This patch provides guarantee to the sysadmin that when TFA is disabled, no PMU event is using PMC3 when the echo command returns. Vice-Versa, when TFA is enabled, PMU can use PMC3 immediately (to eliminate possible multiplexing). $ perf stat -a -I 1000 --no-merge -e branches,branches,branches,branches 1.000123979 125,768,725,208 branches 1.000562520 125,631,000,456 branches 1.000942898 125,487,114,291 branches 1.001333316 125,323,363,620 branches 2.004721306 125,514,968,546 branches 2.005114560 125,511,110,861 branches 2.005482722 125,510,132,724 branches 2.005851245 125,508,967,086 branches 3.006323475 125,166,570,648 branches 3.006709247 125,165,650,056 branches 3.007086605 125,164,639,142 branches 3.007459298 125,164,402,912 branches 4.007922698 125,045,577,140 branches 4.008310775 125,046,804,324 branches 4.008670814 125,048,265,111 branches 4.009039251 125,048,677,611 branches 5.009503373 125,122,240,217 branches 5.009897067 125,122,450,517 branches Then on another connection, sysadmin does: $ echo 1 >/sys/devices/cpu/allow_tsx_force_abort Then perf stat adjusts the events immediately: 5.010286029 125,121,393,483 branches 5.010646308 125,120,556,786 branches 6.011113588 124,963,351,832 branches 6.011510331 124,964,267,566 branches 6.011889913 124,964,829,130 branches 6.012262996 124,965,841,156 branches 7.012708299 124,419,832,234 branches [79.69%] 7.012847908 124,416,363,853 branches [79.73%] 7.013225462 124,400,723,712 branches [79.73%] 7.013598191 124,376,154,434 branches [79.70%] 8.014089834 124,250,862,693 branches [74.98%] 8.014481363 124,267,539,139 branches [74.94%] 8.014856006 124,259,519,786 branches [74.98%] 8.014980848 124,225,457,969 branches [75.04%] 9.015464576 124,204,235,423 branches [75.03%] 9.015858587 124,204,988,490 branches [75.04%] 9.016243680 124,220,092,486 branches [74.99%] 9.016620104 124,231,260,146 branches [74.94%] And vice-versa if the syadmin does: $ echo 0 >/sys/devices/cpu/allow_tsx_force_abort Events are again spread over the 4 counters: 10.017096277 124,276,230,565 branches [74.96%] 10.017237209 124,228,062,171 branches [75.03%] 10.017478637 124,178,780,626 branches [75.03%] 10.017853402 124,198,316,177 branches [75.03%] 11.018334423 124,602,418,933 branches [85.40%] 11.018722584 124,602,921,320 branches [85.42%] 11.019095621 124,603,956,093 branches [85.42%] 11.019467742 124,595,273,783 branches [85.42%] 12.019945736 125,110,114,864 branches 12.020330764 125,109,334,472 branches 12.020688740 125,109,818,865 branches 12.021054020 125,108,594,014 branches 13.021516774 125,109,164,018 branches 13.021903640 125,108,794,510 branches 13.022270770 125,107,756,978 branches 13.022630819 125,109,380,471 branches 14.023114989 125,133,140,817 branches 14.023501880 125,133,785,858 branches 14.023868339 125,133,852,700 branches Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: kan.liang@intel.com Cc: nelson.dsouza@intel.com Cc: tonyj@suse.com Link: https://lkml.kernel.org/r/20190408173252.37932-3-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
3966c3fe |
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02-Apr-2019 |
Lendacky, Thomas <Thomas.Lendacky@amd.com> |
x86/perf/amd: Remove need to check "running" bit in NMI handler Spurious interrupt support was added to perf in the following commit, almost a decade ago: 63e6be6d98e1 ("perf, x86: Catch spurious interrupts after disabling counters") The two previous patches (resolving the race condition when disabling a PMC and NMI latency mitigation) allow for the removal of this older spurious interrupt support. Currently in x86_pmu_stop(), the bit for the PMC in the active_mask bitmap is cleared before disabling the PMC, which sets up a race condition. This race condition was mitigated by introducing the running bitmap. That race condition can be eliminated by first disabling the PMC, waiting for PMC reset on overflow and then clearing the bit for the PMC in the active_mask bitmap. The NMI handler will not re-enable a disabled counter. If x86_pmu_stop() is called from the perf NMI handler, the NMI latency mitigation support will guard against any unhandled NMI messages. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> # 4.14.x- Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: https://lkml.kernel.org/r/Message-ID: Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
f80deefa |
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14-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Add sanity checks to x86_schedule_events() By computing the 'committed' index earlier, we can use it to validate the cached constraint state. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
109717de |
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14-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Optimize x86_schedule_events() Now that cpuc->event_constraint[] is retained, we can avoid calling get_event_constraints() over and over again. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
2c9651c3 |
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14-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Clear ->event_constraint[] on put The current code unconditionally clears cpuc->event_constraint[i] before calling get_event_constraints(.idx=i). The only site that cares is intel_get_event_constraints() where the c1 load will always be NULL. However, always calling get_event_constraints() on all events is wastefull, most times it will return the exact same result. Therefore retain the logic in intel_get_event_constraints() and change the generic code to only clear the constraint on put. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
1f6a1e2d |
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13-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Remove PERF_X86_EVENT_COMMITTED The flag PERF_X86_EVENT_COMMITTED is used to find uncommitted events for which to call put_event_constraint() when scheduling fails. These are the newly added events to the list, and must form, per definition, the tail of cpuc->event_list[]. By computing the list index of the last successfull schedule, then iteration can start there and the flag is redundant. There are only 3 callers of x86_schedule_events(), notably: - x86_pmu_add() - x86_pmu_commit_txn() - validate_group() For x86_pmu_add(), cpuc->n_events isn't updated until after schedule_events() succeeds, therefore cpuc->n_events points to the desired index. For x86_pmu_commit_txn(), cpuc->n_events is updated, but we can trivially compute the desired value with cpuc->n_txn -- the number of events added in this transaction. For validate_group(), we can make the rule for x86_pmu_add() work by simply setting cpuc->n_events to 0 before calling schedule_events(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
21d65555 |
|
14-Mar-2019 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Simplify x86_pmu.get_constraints() interface There is a special case for validate_events() where we'll call x86_pmu.get_constraints(.idx=-1). It's purpose, up until recent, seems to be to avoid taking a previous constraint from cpuc->event_constraint[] in intel_get_event_constraints(). (I could not find any other get_event_constraints() implementation using @idx) However, since that cpuc is freshly allocated, that array will in fact be initialized with NULL pointers, achieving the very same effect. Therefore remove this exception. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d01b1f96 |
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05-Mar-2019 |
Peter Zijlstra (Intel) <peterz@infradead.org> |
perf/x86/intel: Make cpuc allocations consistent The cpuc data structure allocation is different between fake and real cpuc's; use the same code to init/free both. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
81ec3f3c |
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04-Feb-2019 |
Jiri Olsa <jolsa@redhat.com> |
perf/x86: Add check_period PMU callback Vince (and later on Ravi) reported crashes in the BTS code during fuzzing with the following backtrace: general protection fault: 0000 [#1] SMP PTI ... RIP: 0010:perf_prepare_sample+0x8f/0x510 ... Call Trace: <IRQ> ? intel_pmu_drain_bts_buffer+0x194/0x230 intel_pmu_drain_bts_buffer+0x160/0x230 ? tick_nohz_irq_exit+0x31/0x40 ? smp_call_function_single_interrupt+0x48/0xe0 ? call_function_single_interrupt+0xf/0x20 ? call_function_single_interrupt+0xa/0x20 ? x86_schedule_events+0x1a0/0x2f0 ? x86_pmu_commit_txn+0xb4/0x100 ? find_busiest_group+0x47/0x5d0 ? perf_event_set_state.part.42+0x12/0x50 ? perf_mux_hrtimer_restart+0x40/0xb0 intel_pmu_disable_event+0xae/0x100 ? intel_pmu_disable_event+0xae/0x100 x86_pmu_stop+0x7a/0xb0 x86_pmu_del+0x57/0x120 event_sched_out.isra.101+0x83/0x180 group_sched_out.part.103+0x57/0xe0 ctx_sched_out+0x188/0x240 ctx_resched+0xa8/0xd0 __perf_event_enable+0x193/0x1e0 event_function+0x8e/0xc0 remote_function+0x41/0x50 flush_smp_call_function_queue+0x68/0x100 generic_smp_call_function_single_interrupt+0x13/0x30 smp_call_function_single_interrupt+0x3e/0xe0 call_function_single_interrupt+0xf/0x20 </IRQ> The reason is that while event init code does several checks for BTS events and prevents several unwanted config bits for BTS event (like precise_ip), the PERF_EVENT_IOC_PERIOD allows to create BTS event without those checks being done. Following sequence will cause the crash: If we create an 'almost' BTS event with precise_ip and callchains, and it into a BTS event it will crash the perf_prepare_sample() function because precise_ip events are expected to come in with callchain data initialized, but that's not the case for intel_pmu_drain_bts_buffer() caller. Adding a check_period callback to be called before the period is changed via PERF_EVENT_IOC_PERIOD. It will deny the change if the event would become BTS. Plus adding also the limit_period check as well. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20190204123532.GA4794@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
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ed6101bb |
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21-Nov-2018 |
Jiri Olsa <jolsa@kernel.org> |
perf/x86/intel: Move branch tracing setup to the Intel-specific source file Moving branch tracing setup to Intel core object into separate intel_pmu_bts_config function, because it's Intel specific. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20181121101612.16272-1-jolsa@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d4ae5529 |
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06-Sep-2018 |
Jiri Olsa <jolsa@redhat.com> |
perf/x86/intel: Export mem events only if there's PEBS support Memory events depends on PEBS support and access to LDLAT MSR, but we display them in /sys/devices/cpu/events even if the CPU does not provide those, like for KVM guests. That brings the false assumption that those events should be available, while they fail event to open. Separating the mem-* events attributes and merging them with cpu_events only if there's PEBS support detected. We could also check if LDLAT MSR is available, but the PEBS check seems to cover the need now. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20180906135748.GC9577@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
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1182a495 |
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19-Sep-2018 |
Reinette Chatre <reinette.chatre@intel.com> |
perf/x86: Add helper to obtain performance counter index perf_event_read_local() is the safest way to obtain measurements associated with performance events. In some cases the overhead introduced by perf_event_read_local() affects the measurements and the use of rdpmcl() is needed. rdpmcl() requires the index of the performance counter used so a helper is introduced to determine the index used by a provided performance event. The index used by a performance event may change when interrupts are enabled. A check is added to ensure that the index is only accessed with interrupts disabled. Even with this check the use of this counter needs to be done with care to ensure it is queried and used within the same disabled interrupts section. This change introduces a new checkpatch warning: CHECK: extern prototypes should be avoided in .h files +extern int x86_perf_rdpmc_index(struct perf_event *event); This warning was discussed and designated as a false positive in http://lkml.kernel.org/r/20180919091759.GZ24124@hirez.programming.kicks-ass.net Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: acme@kernel.org Cc: gavin.hindman@intel.com Cc: jithu.joseph@intel.com Cc: dave.hansen@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/b277ffa78a51254f5414f7b1bc1923826874566e.1537377064.git.reinette.chatre@intel.com
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6d0ef316 |
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23-Sep-2018 |
Pu Wen <puwen@hygon.cn> |
x86/events: Add Hygon Dhyana support to PMU infrastructure The PMU architecture for the Hygon Dhyana CPU is similar to the AMD Family 17h one. To support it, call amd_pmu_init() to share the AMD PMU initialization flow, and change the PMU name to "HYGON". The Hygon Dhyana CPU supports both legacy and extension PMC MSRs (perf counter registers and event selection registers), so add Hygon Dhyana support in the similar way as AMD does. Signed-off-by: Pu Wen <puwen@hygon.cn> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Borislav Petkov <bp@suse.de> Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: x86@kernel.org Cc: thomas.lendacky@amd.com Link: https://lkml.kernel.org/r/9d93ed54a975f33ef7247e0967960f4ce5d3d990.1537533369.git.puwen@hygon.cn
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#
2766d2ee |
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10-Aug-2018 |
Zubin Mithra <zsm@chromium.org> |
perf/x86: Add __ro_after_init annotations x86_pmu_{format,events,attr,caps}_group is written to in init_hw_perf_events and not modified after. This makes them suitable candidates for annotating as __ro_after_init. Signed-off-by: Zubin Mithra <zsm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: alexander.shishkin@linux.intel.com Cc: groeck@chromium.org Link: http://lkml.kernel.org/r/20180810154314.96710-1-zsm@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
4012e77a |
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29-Aug-2018 |
Andy Lutomirski <luto@kernel.org> |
x86/nmi: Fix NMI uaccess race against CR3 switching A NMI can hit in the middle of context switching or in the middle of switch_mm_irqs_off(). In either case, CR3 might not match current->mm, which could cause copy_from_user_nmi() and friends to read the wrong memory. Fix it by adding a new nmi_uaccess_okay() helper and checking it in copy_from_user_nmi() and in __copy_from_user_nmi()'s callers. Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Rik van Riel <riel@surriel.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jann Horn <jannh@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/dd956eba16646fd0b15c3c0741269dfd84452dac.1535557289.git.luto@kernel.org
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6da2ec56 |
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12-Jun-2018 |
Kees Cook <keescook@chromium.org> |
treewide: kmalloc() -> kmalloc_array() The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
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#
46b1b577 |
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20-Apr-2018 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix possible Spectre-v1 indexing for x86_pmu::event_map() > arch/x86/events/intel/cstate.c:307 cstate_pmu_event_init() warn: potential spectre issue 'pkg_msr' (local cap) > arch/x86/events/intel/core.c:337 intel_pmu_event_map() warn: potential spectre issue 'intel_perfmon_event_map' > arch/x86/events/intel/knc.c:122 knc_pmu_event_map() warn: potential spectre issue 'knc_perfmon_event_map' > arch/x86/events/intel/p4.c:722 p4_pmu_event_map() warn: potential spectre issue 'p4_general_events' > arch/x86/events/intel/p6.c:116 p6_pmu_event_map() warn: potential spectre issue 'p6_perfmon_event_map' > arch/x86/events/amd/core.c:132 amd_pmu_event_map() warn: potential spectre issue 'amd_perfmon_event_map' Userspace controls @attr, sanitize @attr->config before passing it on to x86_pmu::event_map(). Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
ef9ee4ad |
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20-Apr-2018 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix possible Spectre-v1 indexing for hw_perf_event cache_* > arch/x86/events/core.c:319 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_event_ids[cache_type]' (local cap) > arch/x86/events/core.c:319 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_event_ids' (local cap) > arch/x86/events/core.c:328 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_extra_regs[cache_type]' (local cap) > arch/x86/events/core.c:328 set_ext_hw_attr() warn: potential spectre issue 'hw_cache_extra_regs' (local cap) Userspace controls @config which contains 3 (byte) fields used for a 3 dimensional array deref. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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0d55303c |
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13-Mar-2018 |
Deepa Dinamani <deepa.kernel@gmail.com> |
compat: Move compat_timespec/ timeval to compat_time.h All the current architecture specific defines for these are the same. Refactor these common defines to a common header file. The new common linux/compat_time.h is also useful as it will eventually be used to hold all the defines that are needed for compat time types that support non y2038 safe types. New architectures need not have to define these new types as they will only use new y2038 safe syscalls. This file can be deleted after y2038 when we stop supporting non y2038 safe syscalls. The patch also requires an operation similar to: git grep "asm/compat\.h" | cut -d ":" -f 1 | xargs -n 1 sed -i -e "s%asm/compat.h%linux/compat.h%g" Cc: acme@kernel.org Cc: benh@kernel.crashing.org Cc: borntraeger@de.ibm.com Cc: catalin.marinas@arm.com Cc: cmetcalf@mellanox.com Cc: cohuck@redhat.com Cc: davem@davemloft.net Cc: deller@gmx.de Cc: devel@driverdev.osuosl.org Cc: gerald.schaefer@de.ibm.com Cc: gregkh@linuxfoundation.org Cc: heiko.carstens@de.ibm.com Cc: hoeppner@linux.vnet.ibm.com Cc: hpa@zytor.com Cc: jejb@parisc-linux.org Cc: jwi@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: mark.rutland@arm.com Cc: mingo@redhat.com Cc: mpe@ellerman.id.au Cc: oberpar@linux.vnet.ibm.com Cc: oprofile-list@lists.sf.net Cc: paulus@samba.org Cc: peterz@infradead.org Cc: ralf@linux-mips.org Cc: rostedt@goodmis.org Cc: rric@kernel.org Cc: schwidefsky@de.ibm.com Cc: sebott@linux.vnet.ibm.com Cc: sparclinux@vger.kernel.org Cc: sth@linux.vnet.ibm.com Cc: ubraun@linux.vnet.ibm.com Cc: will.deacon@arm.com Cc: x86@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: James Hogan <jhogan@kernel.org> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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631fe154 |
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26-Mar-2018 |
Davidlohr Bueso <dave@stgolabs.net> |
perf/x86: Update rdpmc_always_available static key to the modern API No changes in refcount semantics -- use DEFINE_STATIC_KEY_FALSE() for initialization and replace: static_key_slow_inc|dec() => static_branch_inc|dec() static_key_false() => static_branch_unlikely() Added a '_key' suffix to rdpmc_always_available, for better self-documentation. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Link: http://lkml.kernel.org/r/20180326210929.5244-5-dave@stgolabs.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
174afc3e |
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12-Mar-2018 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Rename confusing 'freerunning PEBS' API and implementation to 'large PEBS' The 'freerunning PEBS' and 'large PEBS' are the same thing. Both of these names appear in the code and in the API, which causes confusion. Rename 'freerunning PEBS' to 'large PEBS' to unify the code, which eliminates the confusion. No functional change. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1520865937-22910-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
2c2a9bbe |
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12-Feb-2018 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Disable userspace RDPMC usage for large PEBS Userspace RDPMC cannot possibly work for large PEBS, which was introduced in: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") When the PEBS interrupt threshold is larger than one, there is no way to get exact auto-reload times and value for userspace RDPMC. Disable the userspace RDPMC usage when large PEBS is enabled. The only exception is when the PEBS interrupt threshold is 1, in which case user-space RDPMC works well even with auto-reload events. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") Link: http://lkml.kernel.org/r/1518474035-21006-6-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org> (cherry picked from commit 1af22eba248efe2de25658041a80a3d40fb3e92e)
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#
edb39592 |
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15-Mar-2018 |
Peter Zijlstra <peterz@infradead.org> |
perf: Fix sibling iteration Mark noticed that the change to sibling_list changed some iteration semantics; because previously we used group_list as list entry, sibling events would always have an empty sibling_list. But because we now use sibling_list for both list head and list entry, siblings will report as having siblings. Fix this with a custom for_each_sibling_event() iterator. Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry") Reported-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: vincent.weaver@maine.edu Cc: alexander.shishkin@linux.intel.com Cc: torvalds@linux-foundation.org Cc: alexey.budankov@linux.intel.com Cc: valery.cherepennikov@intel.com Cc: eranian@google.com Cc: acme@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: davidcc@google.com Cc: kan.liang@intel.com Cc: Dmitry.Prohorov@intel.com Cc: jolsa@redhat.com Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net
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7eb709f2 |
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15-Mar-2018 |
Peter Zijlstra <peterz@infradead.org> |
perf: Fix sibling iteration Mark noticed that the change to sibling_list changed some iteration semantics; because previously we used group_list as list entry, sibling events would always have an empty sibling_list. But because we now use sibling_list for both list head and list entry, siblings will report as having siblings. Fix this with a custom for_each_sibling_event() iterator. Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry") Reported-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: vincent.weaver@maine.edu Cc: alexander.shishkin@linux.intel.com Cc: torvalds@linux-foundation.org Cc: alexey.budankov@linux.intel.com Cc: valery.cherepennikov@intel.com Cc: eranian@google.com Cc: acme@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: davidcc@google.com Cc: kan.liang@intel.com Cc: Dmitry.Prohorov@intel.com Cc: jolsa@redhat.com Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net
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8343aae6 |
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13-Nov-2017 |
Peter Zijlstra <peterz@infradead.org> |
perf/core: Remove perf_event::group_entry Now that all the grouping is done with RB trees, we no longer need group_entry and can replace the whole thing with sibling_list. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Dmitri Prokhorov <Dmitry.Prohorov@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Valery Cherepennikov <valery.cherepennikov@intel.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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1af22eba |
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12-Feb-2018 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Disable userspace RDPMC usage for large PEBS Userspace RDPMC cannot possibly work for large PEBS, which was introduced in: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") When the PEBS interrupt threshold is larger than one, there is no way to get exact auto-reload times and value for userspace RDPMC. Disable the userspace RDPMC usage when large PEBS is enabled. The only exception is when the PEBS interrupt threshold is 1, in which case user-space RDPMC works well even with auto-reload events. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt handling (large PEBS interrupt threshold)") Link: http://lkml.kernel.org/r/1518474035-21006-6-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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bcfbe5c4 |
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12-Feb-2018 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86: Introduce a ->read() callback in 'struct x86_pmu' Auto-reload needs to be specially handled when reading event counts. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Link: http://lkml.kernel.org/r/1518474035-21006-3-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
d31fc13f |
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12-Feb-2018 |
Kan Liang <kan.liang@linux.intel.com> |
perf/x86/intel: Fix event update for auto-reload There is a bug when reading event->count with large PEBS enabled. Here is an example: # ./read_count 0x71f0 0x122c0 0x1000000001c54 0x100000001257d 0x200000000bdc5 In fixed period mode, the auto-reload mechanism could be enabled for PEBS events, but the calculation of event->count does not take the auto-reload values into account. Anyone who reads event->count will get the wrong result, e.g x86_pmu_read(). This bug was introduced with the auto-reload mechanism enabled since commit: 851559e35fd5 ("perf/x86/intel: Use the PEBS auto reload mechanism when possible") Introduce intel_pmu_save_and_restart_reload() to calculate the event->count only for auto-reload. Since the counter increments a negative counter value and overflows on the sign switch, giving the interval: [-period, 0] the difference between two consequtive reads is: A) value2 - value1; when no overflows have happened in between, B) (0 - value1) + (value2 - (-period)); when one overflow happened in between, C) (0 - value1) + (n - 1) * (period) + (value2 - (-period)); when @n overflows happened in between. Here A) is the obvious difference, B) is the extension to the discrete interval, where the first term is to the top of the interval and the second term is from the bottom of the next interval and C) the extension to multiple intervals, where the middle term is the whole intervals covered. The equation for all cases is: value2 - value1 + n * period Previously the event->count is updated right before the sample output. But for case A, there is no PEBS record ready. It needs to be specially handled. Remove the auto-reload code from x86_perf_event_set_period() since we'll not longer call that function in this case. Based-on-code-from: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Fixes: 851559e35fd5 ("perf/x86/intel: Use the PEBS auto reload mechanism when possible") Link: http://lkml.kernel.org/r/1518474035-21006-2-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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3382290e |
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24-Oct-2017 |
Will Deacon <will@kernel.org> |
locking/barriers: Convert users of lockless_dereference() to READ_ONCE() [ Note, this is a Git cherry-pick of the following commit: 506458efaf15 ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()") ... for easier x86 PTI code testing and back-porting. ] READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
6aa7de05 |
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23-Oct-2017 |
Mark Rutland <mark.rutland@arm.com> |
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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506458ef |
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24-Oct-2017 |
Will Deacon <will@kernel.org> |
locking/barriers: Convert users of lockless_dereference() to READ_ONCE() READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
5da382eb |
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27-Aug-2017 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix caps/ for !Intel Move the 'max_precise' capability into generic x86 code where it belongs. This fixes a sysfs splat on !Intel systems where we fail to set x86_pmu_caps_group.atts. Reported-and-tested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andi Kleen <ak@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hpa@zytor.com Fixes: 22688d1c20f5 ("x86/perf: Export some PMU attributes in caps/ directory") Link: http://lkml.kernel.org/r/20170828104650.2u3rsim4jafyjzv2@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
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eaa2f87c |
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18-Aug-2017 |
Dan Carpenter <dan.carpenter@oracle.com> |
x86/ldt: Fix off by one in get_segment_base() ldt->entries[] is allocated in alloc_ldt_struct(). It has ldt->nr_entries elements and ldt->nr_entries is capped at LDT_ENTRIES. So if "idx" is == ldt->nr_entries then we're reading beyond the end of the buffer. It seems duplicative to have two limit checks when one would work just as well so I removed the check against LDT_ENTRIES. The gdt_page.gdt[] array has GDT_ENTRIES entries. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-janitors@vger.kernel.org Fixes: d07bdfd322d3 ("perf/x86: Fix USER/KERNEL tagging of samples properly") Link: http://lkml.kernel.org/r/20170818102516.gqwm4xdvvuvjw5ho@mwanda Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
b00233b5 |
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22-Aug-2017 |
Andi Kleen <ak@linux.intel.com> |
perf/x86: Export some PMU attributes in caps/ directory It can be difficult to figure out for user programs what features the x86 CPU PMU driver actually supports. Currently it requires grepping in dmesg, but dmesg is not always available. This adds a caps directory to /sys/bus/event_source/devices/cpu/, similar to the caps already used on intel_pt, which can be used to discover the available capabilities cleanly. Three capabilities are defined: - pmu_name: Underlying CPU name known to the driver - max_precise: Max precise level supported - branches: Known depth of LBR. Example: % grep . /sys/bus/event_source/devices/cpu/caps/* /sys/bus/event_source/devices/cpu/caps/branches:32 /sys/bus/event_source/devices/cpu/caps/max_precise:3 /sys/bus/event_source/devices/cpu/caps/pmu_name:skylake Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170822185201.9261-3-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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bfe33492 |
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02-Aug-2017 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Fix RDPMC vs. mm_struct tracking Vince reported the following rdpmc() testcase failure: > Failing test case: > > fd=perf_event_open(); > addr=mmap(fd); > exec() // without closing or unmapping the event > fd=perf_event_open(); > addr=mmap(fd); > rdpmc() // GPFs due to rdpmc being disabled The problem is of course that exec() plays tricks with what is current->mm, only destroying the old mappings after having installed the new mm. Fix this confusion by passing along vma->vm_mm instead of relying on current->mm. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 1e0fb9ec679c ("perf: Add pmu callbacks to track event mapping and unmapping") Link: http://lkml.kernel.org/r/20170802173930.cstykcqefmqt7jau@hirez.programming.kicks-ass.net [ Minor cleanups. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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11d8b058 |
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19-Jul-2017 |
Arnd Bergmann <arnd@arndb.de> |
perf/x86: Shut up false-positive -Wmaybe-uninitialized warning The intialization function checks for various failure scenarios, but unfortunately the compiler gets a little confused about the possible combinations, leading to a false-positive build warning when -Wmaybe-uninitialized is set: arch/x86/events/core.c: In function ‘init_hw_perf_events’: arch/x86/events/core.c:264:3: warning: ‘reg_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] arch/x86/events/core.c:264:3: warning: ‘val_fail’ may be used uninitialized in this function [-Wmaybe-uninitialized] pr_err(FW_BUG "the BIOS has corrupted hw-PMU resources (MSR %x is %Lx)\n", We can't actually run into this case, so this shuts up the warning by initializing the variables to a known-invalid state. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170719125310.2487451-2-arnd@arndb.de Link: https://patchwork.kernel.org/patch/9392595/ Signed-off-by: Ingo Molnar <mingo@kernel.org>
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bbf79d21 |
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06-Jun-2017 |
Borislav Petkov <bp@suse.de> |
x86/ldt: Rename ldt_struct::size to ::nr_entries ... because this is exactly what it is: the number of entries in the LDT. Calling it "size" is simply confusing and it is actually begging to be called "nr_entries" or somesuch, especially if you see constructs like: alloc_size = size * LDT_ENTRY_SIZE; since LDT_ENTRY_SIZE is the size of a single entry. There should be no functionality change resulting from this patch, as the before/after output from tools/testing/selftests/x86/ldt_gdt.c shows. Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170606173116.13977-1-bp@alien8.de [ Renamed 'n_entries' to 'nr_entries' ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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3d28ebce |
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28-May-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/mm: Rework lazy TLB to track the actual loaded mm Lazy TLB state is currently managed in a rather baroque manner. AFAICT, there are three possible states: - Non-lazy. This means that we're running a user thread or a kernel thread that has called use_mm(). current->mm == current->active_mm == cpu_tlbstate.active_mm and cpu_tlbstate.state == TLBSTATE_OK. - Lazy with user mm. We're running a kernel thread without an mm and we're borrowing an mm_struct. We have current->mm == NULL, current->active_mm == cpu_tlbstate.active_mm, cpu_tlbstate.state != TLBSTATE_OK (i.e. TLBSTATE_LAZY or 0). The current cpu is set in mm_cpumask(current->active_mm). CR3 points to current->active_mm->pgd. The TLB is up to date. - Lazy with init_mm. This happens when we call leave_mm(). We have current->mm == NULL, current->active_mm == cpu_tlbstate.active_mm, but that mm is only relelvant insofar as the scheduler is tracking it for refcounting. cpu_tlbstate.state != TLBSTATE_OK. The current cpu is clear in mm_cpumask(current->active_mm). CR3 points to swapper_pg_dir, i.e. init_mm->pgd. This patch simplifies the situation. Other than perf, x86 stops caring about current->active_mm at all. We have cpu_tlbstate.loaded_mm pointing to the mm that CR3 references. The TLB is always up to date for that mm. leave_mm() just switches us to init_mm. There are no longer any special cases for mm_cpumask, and switch_mm() switches mms without worrying about laziness. After this patch, cpu_tlbstate.state serves only to tell the TLB flush code whether it may switch to init_mm instead of doing a normal flush. This makes fairly extensive changes to xen_exit_mmap(), which used to look a bit like black magic. Perf is unchanged. With or without this change, perf may behave a bit erratically if it tries to read user memory in kernel thread context. We should build on this patch to teach perf to never look at user memory when cpu_tlbstate.loaded_mm != current->mm. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Nadav Amit <namit@vmware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-mm@kvack.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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27d3b157 |
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24-May-2017 |
Thomas Gleixner <tglx@linutronix.de> |
x86/perf: Drop EXPORT of perf_check_microcode The only caller is the microcode update, which cannot be modular. Drop the export. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Borislav Petkov <bp@suse.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Borislav Petkov <bp@alien8.de> Link: http://lkml.kernel.org/r/20170524081548.515204988@linutronix.de
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#
6089327f |
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12-May-2017 |
Kan Liang <Kan.liang@intel.com> |
perf/x86: Add sysfs entry to freeze counters on SMI Currently, the SMIs are visible to all performance counters, because many users want to measure everything including SMIs. But in some cases, the SMI cycles should not be counted - for example, to calculate the cost of an SMI itself. So a knob is needed. When setting FREEZE_WHILE_SMM bit in IA32_DEBUGCTL, all performance counters will be effected. There is no way to do per-counter freeze on SMI. So it should not use the per-event interface (e.g. ioctl or event attribute) to set FREEZE_WHILE_SMM bit. Adds sysfs entry /sys/device/cpu/freeze_on_smi to set FREEZE_WHILE_SMM bit in IA32_DEBUGCTL. When set, freezes perfmon and trace messages while in SMM. Value has to be 0 or 1. It will be applied to all processors. Also serialize the entire setting so we don't get multiple concurrent threads trying to update to different values. Signed-off-by: Kan Liang <Kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: bp@alien8.de Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1494600673-244667-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
59eaef78 |
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02-May-2017 |
Peter Zijlstra <peterz@infradead.org> |
x86/tsc: Remodel cyc2ns to use seqcount_latch() Replace the custom multi-value scheme with the more regular seqcount_latch() scheme. Along with scrapping a lot of lines, the latch scheme is better documented and used in more places. The immediate benefit however is not being limited on the update side. The current code has a limit where the writers block which is hit by future changes. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
698eff63 |
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16-Mar-2017 |
Peter Zijlstra <peterz@infradead.org> |
sched/clock, x86/perf: Fix "perf test tsc" People reported that commit: 5680d8094ffa ("sched/clock: Provide better clock continuity") broke "perf test tsc". That commit added another offset to the reported clock value; so take that into account when computing the provided offset values. Reported-by: Adrian Hunter <adrian.hunter@intel.com> Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 5680d8094ffa ("sched/clock: Provide better clock continuity") Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
4b07372a |
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16-Mar-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/perf: Clarify why x86_pmu_event_mapped() isn't racy Naively, it looks racy, but ->mmap_sem saves it. Add a comment and a lockdep assertion. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/03a1e629063899168dfc4707f3bb6e581e21f5c6.1489694270.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
5dc855d4 |
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16-Mar-2017 |
Andy Lutomirski <luto@kernel.org> |
x86/perf: Fix CR4.PCE propagation to use active_mm instead of mm If one thread mmaps a perf event while another thread in the same mm is in some context where active_mm != mm (which can happen in the scheduler, for example), refresh_pce() would write the wrong value to CR4.PCE. This broke some PAPI tests. Reported-and-tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bpetkov@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Fixes: 7911d3f7af14 ("perf/x86: Only allow rdpmc if a perf_event is mapped") Link: http://lkml.kernel.org/r/0c5b38a76ea50e405f9abe07a13dfaef87c173a1.1489694270.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
589ee628 |
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03-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> Update code that relied on sched.h including various MM types for them. This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
e6017571 |
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01-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Prepare for new header dependencies before moving code to <linux/sched/clock.h> We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which will have to be picked up from other headers and .c files. Create a trivial placeholder <linux/sched/clock.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
18e7a45a |
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03-Jan-2017 |
Jiri Olsa <jolsa@redhat.com> |
perf/x86: Reject non sampling events with precise_ip As Peter suggested [1] rejecting non sampling PEBS events, because they dont make any sense and could cause bugs in the NMI handler [2]. [1] http://lkml.kernel.org/r/20170103094059.GC3093@worktop [2] http://lkml.kernel.org/r/1482931866-6018-3-git-send-email-jolsa@kernel.org Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vince@deater.net> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20170103142454.GA26251@krava Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
73c1b41e |
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21-Dec-2016 |
Thomas Gleixner <tglx@linutronix.de> |
cpu/hotplug: Cleanup state names When the state names got added a script was used to add the extra argument to the calls. The script basically converted the state constant to a string, but the cleanup to convert these strings into meaningful ones did not happen. Replace all the useless strings with 'subsys/xxx/yyy:state' strings which are used in all the other places already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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#
b0c1ef52 |
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08-Dec-2016 |
Andi Kleen <ak@linux.intel.com> |
perf/x86: Fix exclusion of BTS and LBR for Goldmont An earlier patch allowed enabling PT and LBR at the same time on Goldmont. However it also allowed enabling BTS and LBR at the same time, which is still not supported. Fix this by bypassing the check only for PT. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: alexander.shishkin@intel.com Cc: kan.liang@intel.com Cc: <stable@vger.kernel.org> Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") Link: http://lkml.kernel.org/r/20161209001417.4713-1-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
990e9dc3 |
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09-Dec-2016 |
Thomas Gleixner <tglx@linutronix.de> |
x86/ldt: Make all size computations unsigned ldt->size can never be negative. The helper functions take 'unsigned int' arguments which are assigned from ldt->size. The related user space user_desc struct member entry_number is unsigned as well. But ldt->size itself and a few local variables which are related to ldt->size are type 'int' which makes no sense whatsoever and results in typecasts which make the eyes bleed. Clean it up and convert everything which is related to ldt->size to unsigned it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dan Carpenter <dan.carpenter@oracle.com>
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#
7f612a7f |
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29-Nov-2016 |
Peter Zijlstra (Intel) <peterz@infradead.org> |
perf/x86: Fix full width counter, counter overflow Lukasz reported that perf stat counters overflow handling is broken on KNL/SLM. Both these parts have full_width_write set, and that does indeed have a problem. In order to deal with counter wrap, we must sample the counter at at least half the counter period (see also the sampling theorem) such that we can unambiguously reconstruct the count. However commit: 069e0c3c4058 ("perf/x86/intel: Support full width counting") sets the sampling interval to the full period, not half. Fixing that exposes another issue, in that we must not sign extend the delta value when we shift it right; the counter cannot have decremented after all. With both these issues fixed, counter overflow functions correctly again. Reported-by: Lukasz Odzioba <lukasz.odzioba@intel.com> Tested-by: Liang, Kan <kan.liang@intel.com> Tested-by: Odzioba, Lukasz <lukasz.odzioba@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org Fixes: 069e0c3c4058 ("perf/x86/intel: Support full width counting") Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
ae31fe51 |
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22-Nov-2016 |
Johannes Weiner <hannes@cmpxchg.org> |
perf/x86: Restore TASK_SIZE check on frame pointer The following commit: 75925e1ad7f5 ("perf/x86: Optimize stack walk user accesses") ... switched from copy_from_user_nmi() to __copy_from_user_nmi() with a manual access_ok() check. Unfortunately, copy_from_user_nmi() does an explicit check against TASK_SIZE, whereas the access_ok() uses whatever the current address limit of the task is. We are getting NMIs when __probe_kernel_read() has switched to KERNEL_DS, and then see vmalloc faults when we access what looks like pointers into vmalloc space: [] WARNING: CPU: 3 PID: 3685731 at arch/x86/mm/fault.c:435 vmalloc_fault+0x289/0x290 [] CPU: 3 PID: 3685731 Comm: sh Tainted: G W 4.6.0-5_fbk1_223_gdbf0f40 #1 [] Call Trace: [] <NMI> [<ffffffff814717d1>] dump_stack+0x4d/0x6c [] [<ffffffff81076e43>] __warn+0xd3/0xf0 [] [<ffffffff81076f2d>] warn_slowpath_null+0x1d/0x20 [] [<ffffffff8104a899>] vmalloc_fault+0x289/0x290 [] [<ffffffff8104b5a0>] __do_page_fault+0x330/0x490 [] [<ffffffff8104b70c>] do_page_fault+0xc/0x10 [] [<ffffffff81794e82>] page_fault+0x22/0x30 [] [<ffffffff81006280>] ? perf_callchain_user+0x100/0x2a0 [] [<ffffffff8115124f>] get_perf_callchain+0x17f/0x190 [] [<ffffffff811512c7>] perf_callchain+0x67/0x80 [] [<ffffffff8114e750>] perf_prepare_sample+0x2a0/0x370 [] [<ffffffff8114e840>] perf_event_output+0x20/0x60 [] [<ffffffff8114aee7>] ? perf_event_update_userpage+0xc7/0x130 [] [<ffffffff8114ea01>] __perf_event_overflow+0x181/0x1d0 [] [<ffffffff8114f484>] perf_event_overflow+0x14/0x20 [] [<ffffffff8100a6e3>] intel_pmu_handle_irq+0x1d3/0x490 [] [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10 [] [<ffffffff81197191>] ? vunmap_page_range+0x1a1/0x2f0 [] [<ffffffff811972f1>] ? unmap_kernel_range_noflush+0x11/0x20 [] [<ffffffff814f2056>] ? ghes_copy_tofrom_phys+0x116/0x1f0 [] [<ffffffff81040d1d>] ? x2apic_send_IPI_self+0x1d/0x20 [] [<ffffffff8100411d>] perf_event_nmi_handler+0x2d/0x50 [] [<ffffffff8101ea31>] nmi_handle+0x61/0x110 [] [<ffffffff8101ef94>] default_do_nmi+0x44/0x110 [] [<ffffffff8101f13b>] do_nmi+0xdb/0x150 [] [<ffffffff81795187>] end_repeat_nmi+0x1a/0x1e [] [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10 [] [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10 [] [<ffffffff8147daf7>] ? copy_user_enhanced_fast_string+0x7/0x10 [] <<EOE>> <IRQ> [<ffffffff8115d05e>] ? __probe_kernel_read+0x3e/0xa0 Fix this by moving the valid_user_frame() check to before the uaccess that loads the return address and the pointer to the next frame. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Fixes: 75925e1ad7f5 ("perf/x86: Optimize stack walk user accesses") Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
35f4d9b3 |
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16-Sep-2016 |
Josh Poimboeuf <jpoimboe@redhat.com> |
perf/x86: Convert perf_callchain_kernel() to use the new unwinder Convert perf_callchain_kernel() to use the new unwinder. dump_trace() has been deprecated. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a2df0c4f09b3d438e11b41681f10b0775a819a7f.1474045023.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
cb76c939 |
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14-Sep-2016 |
Josh Poimboeuf <jpoimboe@redhat.com> |
x86/dumpstack: Add get_stack_info() interface valid_stack_ptr() is buggy: it assumes that all stacks are of size THREAD_SIZE, which is not true for exception stacks. So the walk_stack() callbacks will need to know the location of the beginning of the stack as well as the end. Another issue is that in general the various features of a stack (type, size, next stack pointer, description string) are scattered around in various places throughout the stack dump code. Encapsulate all that information in a single place with a new stack_info struct and a get_stack_info() interface. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8164dd0db96b7e6a279fa17ae5e6dc375eecb4a9.1473905218.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
019e579d |
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24-Aug-2016 |
Josh Poimboeuf <jpoimboe@redhat.com> |
perf/x86: Check perf_callchain_store() error Add a check to perf_callchain_kernel() so that it returns early if the callchain entry array is already full. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Brian Gerst <brgerst@gmail.com> Cc: Byungchul Park <byungchul.park@lge.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/dce6d60bab08be2600efd90021d9b85620646161.1472057064.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
68f7082f |
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06-Jul-2016 |
Peter Zijlstra <peterz@infradead.org> |
perf/x86: Ensure perf_sched_cb_{inc,dec}() is only called from pmu::{add,del}() Currently perf_sched_cb_{inc,dec}() are called from pmu::{start,stop}(), which has the problem that this can happen from NMI context, this is making it hard to optimize perf_pmu_sched_task(). Furthermore, we really only need this accounting on pmu::{add,del}(), so doing it from pmu::{start,stop}() is doing more work than we really need. Introduce x86_pmu::{add,del}() and wire up the LBR and PEBS. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
005bd007 |
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01-Aug-2016 |
Juergen Gross <jgross@suse.com> |
perf/x86: Modify error message in virtualized environment It is known that PMU isn't working in some virtualized environments. Modify the message issued in that case to mention why hardware PMU isn't usable instead of reporting it to be broken. As a side effect this will correct a little bug in the error message: The error message was meant to be either of level err or info depending on the environment (native or virtualized). As the level is taken from the format string and not the printed string, specifying it via %s and a conditional argument didn't work the way intended. Signed-off-by: Juergen Gross <jgross@suse.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Link: http://lkml.kernel.org/r/1470051427-16795-1-git-send-email-jgross@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
eb008eb6 |
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13-Jul-2016 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
x86: Audit and remove any remaining unnecessary uses of module.h Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. In the case of some of these which are modular, we can extend that to also include files that are building basic support functionality but not related to loading or registering the final module; such files also have no need whatsoever for module.h The advantage in removing such instances is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each instance for the presence of either and replace as needed. In the case of crypto/glue_helper.c we delete a redundant instance of MODULE_LICENSE in order to delete module.h -- the license info is already present at the top of the file. The uncore change warrants a mention too; it is uncore.c that uses module.h and not uncore.h; hence the relocation done there. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20160714001901.31603-9-paul.gortmaker@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
95ca792c |
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13-Jul-2016 |
Thomas Gleixner <tglx@linutronix.de> |
perf/x86: Convert the core to the hotplug state machine Replace the perf_notifier() install mechanism, which invokes magically the callback on the current CPU. Convert the hardware specific callbacks which are invoked from the x86 perf core to return proper error codes instead of totally pointless NOTIFY_BAD return values. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Adam Borowski <kilobyte@angband.pl> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153333.670720553@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
eb019503 |
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10-Jul-2016 |
Vegard Nossum <vegard.nossum@oracle.com> |
perf/x86: Fix bogus kernel printk, again This showed up as "6Failed to access..." here. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Chen Yucong <slaoub@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 1b74dde7c47c ("x86/cpu: Convert printk(KERN_<LEVEL> ...) to pr_<level>(...)") Link: http://lkml.kernel.org/r/1468170841-17045-1-git-send-email-vegard.nossum@oracle.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
fc188225 |
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01-Jul-2016 |
Josh Poimboeuf <jpoimboe@redhat.com> |
perf/x86: Fix 32-bit perf user callgraph collection A basic perf callgraph record operation causes an immediate panic on a 32-bit kernel compiled with CONFIG_CC_STACKPROTECTOR=y: $ perf record -g ls Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: c0404fbd CPU: 0 PID: 998 Comm: ls Not tainted 4.7.0-rc5+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 c0dd5967 ff7afe1c 00000086 f41dbc2c c07445a0 464c457f f41dbca8 f41dbc44 c05646f4 f41dbca8 464c457f f41dbca8 464c457f f41dbc54 c04625be c0ce56fc c0404fbd f41dbc88 c0404fbd b74668f0 f41dc000 00000000 c0000000 00000000 Call Trace: [<c07445a0>] dump_stack+0x58/0x78 [<c05646f4>] panic+0x8e/0x1c6 [<c04625be>] __stack_chk_fail+0x1e/0x30 [<c0404fbd>] ? perf_callchain_user+0x22d/0x230 [<c0404fbd>] perf_callchain_user+0x22d/0x230 [<c055f89f>] get_perf_callchain+0x1ff/0x270 [<c055f988>] perf_callchain+0x78/0x90 [<c055c7eb>] perf_prepare_sample+0x24b/0x370 [<c055c934>] perf_event_output_forward+0x24/0x70 [<c05531c0>] __perf_event_overflow+0xa0/0x210 [<c0550a93>] ? cpu_clock_event_read+0x43/0x50 [<c0553431>] perf_swevent_hrtimer+0x101/0x180 [<c0456235>] ? kmap_atomic_prot+0x35/0x140 [<c056dc69>] ? get_page_from_freelist+0x279/0x950 [<c058fdd8>] ? vma_interval_tree_remove+0x158/0x230 [<c05939f4>] ? wp_page_copy.isra.82+0x2f4/0x630 [<c05a050d>] ? page_add_file_rmap+0x1d/0x50 [<c0565611>] ? unlock_page+0x61/0x80 [<c0566755>] ? filemap_map_pages+0x305/0x320 [<c059769f>] ? handle_mm_fault+0xb7f/0x1560 [<c074cbeb>] ? timerqueue_del+0x1b/0x70 [<c04cfefe>] ? __remove_hrtimer+0x2e/0x60 [<c04d017b>] __hrtimer_run_queues+0xcb/0x2a0 [<c0553330>] ? __perf_event_overflow+0x210/0x210 [<c04d0a2a>] hrtimer_interrupt+0x8a/0x180 [<c043ecc2>] local_apic_timer_interrupt+0x32/0x60 [<c043f643>] smp_apic_timer_interrupt+0x33/0x50 [<c0b0cd38>] apic_timer_interrupt+0x34/0x3c Kernel Offset: disabled ---[ end Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: c0404fbd The panic is caused by the fact that perf_callchain_user() mistakenly assumes it's 64-bit only and ends up corrupting the stack. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org # v4.5+ Fixes: 75925e1ad7f5 ("perf/x86: Optimize stack walk user accesses") Link: http://lkml.kernel.org/r/1a547f5077ec30f75f9b57074837c3c80df86e5e.1467432113.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
fc07e9f9 |
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19-May-2016 |
Andi Kleen <ak@linux.intel.com> |
perf/x86: Support sysfs files depending on SMT status Add a way to show different sysfs events attributes depending on HyperThreading is on or off. This is difficult to determine early at boot, so we just do it dynamically when the sysfs attribute is read. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-3-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
3b1fff08 |
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10-May-2016 |
Arnaldo Carvalho de Melo <acme@redhat.com> |
perf core: Add a 'nr' field to perf_event_callchain_context We will use it to count how many addresses are in the entry->ip[] array, excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really return the number of entries specified by the user via the relevant sysctl, kernel.perf_event_max_contexts, or via the per event perf_event_attr.sample_max_stack knob. This way we keep the perf_sample->ip_callchain->nr meaning, that is the number of entries, be it real addresses or PERF_CONTEXT_ entries, while honouring the max_stack knobs, i.e. the end result will be max_stack entries if we have at least that many entries in a given stack trace. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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#
cfbcf468 |
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27-Apr-2016 |
Arnaldo Carvalho de Melo <acme@redhat.com> |
perf core: Pass max stack as a perf_callchain_entry context This makes perf_callchain_{user,kernel}() receive the max stack as context for the perf_callchain_entry, instead of accessing the global sysctl_perf_event_max_stack. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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#
ccbebba4 |
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28-Apr-2016 |
Alexander Shishkin <alexander.shishkin@linux.intel.com> |
perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it Not all cores prevent using Intel PT and LBRs simultaneously, although most of them still do as of today. This patch adds an opt-in flag for such cores to disable mutual exclusivity between PT and LBR; also flip it on for Goldmont. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1461857746-31346-4-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c5dfd78e |
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20-Apr-2016 |
Arnaldo Carvalho de Melo <acme@redhat.com> |
perf core: Allow setting up max frame stack depth via sysctl The default remains 127, which is good for most cases, and not even hit most of the time, but then for some cases, as reported by Brendan, 1024+ deep frames are appearing on the radar for things like groovy, ruby. And in some workloads putting a _lower_ cap on this may make sense. One that is per event still needs to be put in place tho. The new file is: # cat /proc/sys/kernel/perf_event_max_stack 127 Chaging it: # echo 256 > /proc/sys/kernel/perf_event_max_stack # cat /proc/sys/kernel/perf_event_max_stack 256 But as soon as there is some event using callchains we get: # echo 512 > /proc/sys/kernel/perf_event_max_stack -bash: echo: write error: Device or resource busy # Because we only allocate the callchain percpu data structures when there is a user, which allows for changing the max easily, its just a matter of having no callchain users at that point. Reported-and-Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: David Ahern <dsahern@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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#
f454bfdd |
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14-Apr-2016 |
Alexander Shishkin <alexander.shishkin@linux.intel.com> |
perf/core, sched: Don't use clock function pointer to determine clock Now that local_clock() is explicitly inlined in sched.h, taking its pointer would uninline it in the compilation unit where it's done, making (among other things) comparing pointers to this function produce different results in different compilation units. Case in point, x86 perf core's user page updating function compares event's clock against &local_clock to see if it needs to set zero time offset related bits in the page. This patch fixes the latter by looking at the "use_clockid" event attribute instead, to determine whether local clock is used. Fixing the uninlined local_clock() in perf core is left as an exercise for the author of the prior work. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Cc: vince@deater.net Fixes: http://lkml.kernel.org/r/1459541050-13654-1-git-send-email-daniel.lezcano@linaro.org Link: http://lkml.kernel.org/r/1460635189-2320-1-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
93984fbd |
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04-Apr-2016 |
Borislav Petkov <bp@suse.de> |
x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: iommu@lists.linux-foundation.org Cc: linux-pm@vger.kernel.org Cc: oprofile-list@lists.sf.net Link: http://lkml.kernel.org/r/1459801503-15600-8-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c7ab62bf |
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08-Mar-2016 |
Huang Rui <ray.huang@amd.com> |
perf/x86/amd/power: Add AMD accumulated power reporting mechanism Introduce an AMD accumlated power reporting mechanism for the Family 15h, Model 60h processor that can be used to calculate the average power consumed by a processor during a measurement interval. The feature support is indicated by CPUID Fn8000_0007_EDX[12]. This feature will be implemented both in hwmon and perf. The current design provides one event to report per package/processor power consumption by counting each compute unit power value. Here the gory details of how the computation is done: * Tsample: compute unit power accumulator sample period * Tref: the PTSC counter period (PTSC: performance timestamp counter) * N: the ratio of compute unit power accumulator sample period to the PTSC period * Jmax: max compute unit accumulated power which is indicated by MSR_C001007b[MaxCpuSwPwrAcc] * Jx/Jy: compute unit accumulated power which is indicated by MSR_C001007a[CpuSwPwrAcc] * Tx/Ty: the value of performance timestamp counter which is indicated by CU_PTSC MSR_C0010280[PTSC] * PwrCPUave: CPU average power i. Determine the ratio of Tsample to Tref by executing CPUID Fn8000_0007. N = value of CPUID Fn8000_0007_ECX[CpuPwrSampleTimeRatio[15:0]]. ii. Read the full range of the cumulative energy value from the new MSR MaxCpuSwPwrAcc. Jmax = value returned. iii. At time x, software reads CpuSwPwrAcc and samples the PTSC. Jx = value read from CpuSwPwrAcc and Tx = value read from PTSC. iv. At time y, software reads CpuSwPwrAcc and samples the PTSC. Jy = value read from CpuSwPwrAcc and Ty = value read from PTSC. v. Calculate the average power consumption for a compute unit over time period (y-x). Unit of result is uWatt: if (Jy < Jx) // Rollover has occurred Jdelta = (Jy + Jmax) - Jx else Jdelta = Jy - Jx PwrCPUave = N * Jdelta * 1000 / (Ty - Tx) Simple example: root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' make -j4 CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL scripts/checksyscalls.sh CHK include/generated/compile.h SKIPPED include/generated/compile.h Building modules, stage 2. Kernel: arch/x86/boot/bzImage is ready (#40) MODPOST 4225 modules Performance counter stats for 'system wide': 183.44 mWatts power/power-pkg/ 341.837270111 seconds time elapsed root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' sleep 10 Performance counter stats for 'system wide': 0.18 mWatts power/power-pkg/ 10.012551815 seconds time elapsed Suggested-by: Peter Zijlstra <peterz@infradead.org> Suggested-by: Ingo Molnar <mingo@kernel.org> Suggested-by: Borislav Petkov <bp@suse.de> Signed-off-by: Huang Rui <ray.huang@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Robert Richter <rric@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: jacob.w.shin@gmail.com Link: http://lkml.kernel.org/r/1457502306-2559-1-git-send-email-ray.huang@amd.com [ Fixed the modular build. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c3d266c8 |
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03-Mar-2016 |
Kan Liang <kan.liang@intel.com> |
perf/x86/intel: Fix PEBS warning by only restoring active PMU in pmi This patch tries to fix a PEBS warning found in my stress test. The following perf command can easily trigger the pebs warning or spurious NMI error on Skylake/Broadwell/Haswell platforms: sudo perf record -e 'cpu/umask=0x04,event=0xc4/pp,cycles,branches,ref-cycles,cache-misses,cache-references' --call-graph fp -b -c1000 -a Also the NMI watchdog must be enabled. For this case, the events number is larger than counter number. So perf has to do multiplexing. In perf_mux_hrtimer_handler, it does perf_pmu_disable(), schedule out old events, rotate_ctx, schedule in new events and finally perf_pmu_enable(). If the old events include precise event, the MSR_IA32_PEBS_ENABLE should be cleared when perf_pmu_disable(). The MSR_IA32_PEBS_ENABLE should keep 0 until the perf_pmu_enable() is called and the new event is precise event. However, there is a corner case which could restore PEBS_ENABLE to stale value during the above period. In perf_pmu_disable(), GLOBAL_CTRL will be set to 0 to stop overflow and followed PMI. But there may be pending PMI from an earlier overflow, which cannot be stopped. So even GLOBAL_CTRL is cleared, the kernel still be possible to get PMI. At the end of the PMI handler, __intel_pmu_enable_all() will be called, which will restore the stale values if old events haven't scheduled out. Once the stale pebs value is set, it's impossible to be corrected if the new events are non-precise. Because the pebs_enabled will be set to 0. x86_pmu.enable_all() will ignore the MSR_IA32_PEBS_ENABLE setting. As a result, the following NMI with stale PEBS_ENABLE trigger pebs warning. The pending PMI after enabled=0 will become harmless if the NMI handler does not change the state. This patch checks cpuc->enabled in pmi and only restore the state when PMU is active. Here is the dump: Call Trace: <NMI> [<ffffffff813c3a2e>] dump_stack+0x63/0x85 [<ffffffff810a46f2>] warn_slowpath_common+0x82/0xc0 [<ffffffff810a483a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8100fe2e>] intel_pmu_drain_pebs_nhm+0x2be/0x320 [<ffffffff8100caa9>] intel_pmu_handle_irq+0x279/0x460 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff811f290d>] ? vunmap_page_range+0x20d/0x330 [<ffffffff811f2f11>] ? unmap_kernel_range_noflush+0x11/0x20 [<ffffffff8148379f>] ? ghes_copy_tofrom_phys+0x10f/0x2a0 [<ffffffff814839c8>] ? ghes_read_estatus+0x98/0x170 [<ffffffff81005a7d>] perf_event_nmi_handler+0x2d/0x50 [<ffffffff810310b9>] nmi_handle+0x69/0x120 [<ffffffff810316f6>] default_do_nmi+0xe6/0x100 [<ffffffff810317f2>] do_nmi+0xe2/0x130 [<ffffffff817aea71>] end_repeat_nmi+0x1a/0x1e [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 [<ffffffff810639b6>] ? native_write_msr_safe+0x6/0x40 <<EOE>> <IRQ> [<ffffffff81006df8>] ? x86_perf_event_set_period+0xd8/0x180 [<ffffffff81006eec>] x86_pmu_start+0x4c/0x100 [<ffffffff8100722d>] x86_pmu_enable+0x28d/0x300 [<ffffffff811994d7>] perf_pmu_enable.part.81+0x7/0x10 [<ffffffff8119cb70>] perf_mux_hrtimer_handler+0x200/0x280 [<ffffffff8119c970>] ? __perf_install_in_context+0xc0/0xc0 [<ffffffff8110f92d>] __hrtimer_run_queues+0xfd/0x280 [<ffffffff811100d8>] hrtimer_interrupt+0xa8/0x190 [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff81051bd8>] local_apic_timer_interrupt+0x38/0x60 [<ffffffff817af01d>] smp_apic_timer_interrupt+0x3d/0x50 [<ffffffff817ad15c>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff81123de5>] ? smp_call_function_single+0xd5/0x130 [<ffffffff81123ddb>] ? smp_call_function_single+0xcb/0x130 [<ffffffff81199080>] ? __perf_read_group_add.part.61+0x1a0/0x1a0 [<ffffffff8119765a>] event_function_call+0x10a/0x120 [<ffffffff8119c660>] ? ctx_resched+0x90/0x90 [<ffffffff811971e0>] ? cpu_clock_event_read+0x30/0x30 [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60 [<ffffffff8119772b>] _perf_event_enable+0x5b/0x70 [<ffffffff81197388>] perf_event_for_each_child+0x38/0xa0 [<ffffffff811976d0>] ? _perf_event_disable+0x60/0x60 [<ffffffff811a0ffd>] perf_ioctl+0x12d/0x3c0 [<ffffffff8134d855>] ? selinux_file_ioctl+0x95/0x1e0 [<ffffffff8124a3a1>] do_vfs_ioctl+0xa1/0x5a0 [<ffffffff81036d29>] ? sched_clock+0x9/0x10 [<ffffffff8124a919>] SyS_ioctl+0x79/0x90 [<ffffffff817ac4b2>] entry_SYSCALL_64_fastpath+0x1a/0xa4 ---[ end trace aef202839fe9a71d ]--- Uhhuh. NMI received for unknown reason 2d on CPU 2. Do you have a strange power saving mode enabled? Signed-off-by: Kan Liang <kan.liang@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1457046448-6184-1-git-send-email-kan.liang@intel.com [ Fixed various typos and other small details. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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27f6d22b |
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10-Feb-2016 |
Borislav Petkov <bp@suse.de> |
perf/x86: Move perf_event.h to its new home Now that all functionality has been moved to arch/x86/events/, move the perf_event.h header and adjust include paths. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1455098123-11740-18-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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fa9cbf32 |
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08-Feb-2016 |
Borislav Petkov <bp@suse.de> |
perf/x86: Move perf_event.c ............... => x86/events/core.c Also, keep the churn at minimum by adjusting the include "perf_event.h" when each file gets moved. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1454947748-28629-2-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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