Searched +hist:11 +hist:a19c7b (Results 1 - 3 of 3) sorted by relevance
/linux-master/kernel/sched/ | ||
H A D | wait.c | diff 11c7aa0d Mon Jun 07 05:26:13 MDT 2021 Jan Kara <jack@suse.cz> rq-qos: fix missed wake-ups in rq_qos_throttle try two Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") tried to fix a problem that a process could be sleeping in rq_qos_wait() without anyone to wake it up. However the fix is not complete and the following can still happen: CPU1 (waiter1) CPU2 (waiter2) CPU3 (waker) rq_qos_wait() rq_qos_wait() acquire_inflight_cb() -> fails acquire_inflight_cb() -> fails completes IOs, inflight decreased prepare_to_wait_exclusive() prepare_to_wait_exclusive() has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers has_sleeper = !wq_has_single_sleeper() -> true io_schedule() io_schedule() Deadlock as now there's nobody to wakeup the two waiters. The logic automatically blocking when there are already sleepers is really subtle and the only way to make it work reliably is that we check whether there are some waiters in the queue when adding ourselves there. That way, we are guaranteed that at least the first process to enter the wait queue will recheck the waiting condition before going to sleep and thus guarantee forward progress. Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> diff 016190a4 Tue Jun 11 06:29:07 MDT 2019 Pavel Begunkov <asml.silence@gmail.com> sched/wait: Deduplicate code with do-while Statements in the loop's body and before it are identical. Use do-while to not repeat it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.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/43ffea6ee2152b90dedf962eac851609e4197218.1560256112.git.asml.silence@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org> diff 11a19c7b Fri Aug 25 10:13:55 MDT 2017 Tim Chen <tim.c.chen@linux.intel.com> sched/wait: Introduce wakeup boomark in wake_up_page_bit Now that we have added breaks in the wait queue scan and allow bookmark on scan position, we put this logic in the wake_up_page_bit function. We can have very long page wait list in large system where multiple pages share the same wait list. We break the wake up walk here to allow other cpus a chance to access the list, and not to disable the interrupts when traversing the list for too long. This reduces the interrupt and rescheduling latency, and excessive page wait queue lock hold time. [ v2: Remove bookmark_wake_function ] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 11a19c7b Fri Aug 25 10:13:55 MDT 2017 Tim Chen <tim.c.chen@linux.intel.com> sched/wait: Introduce wakeup boomark in wake_up_page_bit Now that we have added breaks in the wait queue scan and allow bookmark on scan position, we put this logic in the wake_up_page_bit function. We can have very long page wait list in large system where multiple pages share the same wait list. We break the wake up walk here to allow other cpus a chance to access the list, and not to disable the interrupts when traversing the list for too long. This reduces the interrupt and rescheduling latency, and excessive page wait queue lock hold time. [ v2: Remove bookmark_wake_function ] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 174cd4b1 Thu Feb 02 11:15:33 MST 2017 Ingo Molnar <mingo@kernel.org> sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h> Fix up affected files that include this signal functionality via 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> diff 9dcb8b68 Wed Oct 26 11:15:30 MDT 2016 Linus Torvalds <torvalds@linux-foundation.org> mm: remove per-zone hashtable of bitlock waitqueues The per-zone waitqueues exist because of a scalability issue with the page waitqueues on some NUMA machines, but it turns out that they hurt normal loads, and now with the vmalloced stacks they also end up breaking gfs2 that uses a bit_wait on a stack object: wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE) where 'gh' can be a reference to the local variable 'mount_gh' on the stack of fill_super(). The reason the per-zone hash table breaks for this case is that there is no "zone" for virtual allocations, and trying to look up the physical page to get at it will fail (with a BUG_ON()). It turns out that I actually complained to the mm people about the per-zone hash table for another reason just a month ago: the zone lookup also hurts the regular use of "unlock_page()" a lot, because the zone lookup ends up forcing several unnecessary cache misses and generates horrible code. As part of that earlier discussion, we had a much better solution for the NUMA scalability issue - by just making the page lock have a separate contention bit, the waitqueue doesn't even have to be looked at for the normal case. Peter Zijlstra already has a patch for that, but let's see if anybody even notices. In the meantime, let's fix the actual gfs2 breakage by simplifying the bitlock waitqueues and removing the per-zone issue. Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Tested-by: Bob Peterson <rpeterso@redhat.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff dfd01f02 Sun Dec 13 14:11:16 MST 2015 Peter Zijlstra <peterz@infradead.org> sched/wait: Fix the signal handling fix Jan Stancek reported that I wrecked things for him by fixing things for Vladimir :/ His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which should not be possible, however my previous patch made this possible by unconditionally checking signal_pending(). We cannot use current->state as was done previously, because the instruction after the store to that variable it can be changed. We must instead pass the initial state along and use that. Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers") Reported-by: Jan Stancek <jstancek@redhat.com> Reported-by: Chris Mason <clm@fb.com> Tested-by: Jan Stancek <jstancek@redhat.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Chris Mason <clm@fb.com> Reviewed-by: Paul Turner <pjt@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: tglx@linutronix.de Cc: Oleg Nesterov <oleg@redhat.com> Cc: hpa@zytor.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 4e857c58 Mon Mar 17 11:06:10 MDT 2014 Peter Zijlstra <peterz@infradead.org> arch: Mass conversion of smp_mb__*() Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 7a6354e2 Thu Oct 31 11:07:08 MDT 2013 Peter Zijlstra <peterz@infradead.org> sched: Move wait.c into kernel/sched/ Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-5q5yqvdaen0rmapwloeaotx3@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
/linux-master/include/linux/ | ||
H A D | wait.h | diff 6dfeff09 Mon Dec 11 11:14:41 MST 2023 Matthew Wilcox (Oracle) <willy@infradead.org> wait: Remove uapi header file from main header file There's really no overlap between uapi/linux/wait.h and linux/wait.h. There are two files which rely on the uapi file being implcitly included, so explicitly include it there and remove it from the main header file. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Christian Brauner <brauner@kernel.org> diff 6dfeff09 Mon Dec 11 11:14:41 MST 2023 Matthew Wilcox (Oracle) <willy@infradead.org> wait: Remove uapi header file from main header file There's really no overlap between uapi/linux/wait.h and linux/wait.h. There are two files which rely on the uapi file being implcitly included, so explicitly include it there and remove it from the main header file. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Christian Brauner <brauner@kernel.org> diff 77eccd0d Tue Jun 01 09:11:20 MDT 2021 Julian Wiedmann <jwi@linux.ibm.com> wait: use LIST_HEAD_INIT() to initialize wait_queue_head Replace the open-coded initialization with the right macro. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210601151120.329223-1-jwi@linux.ibm.com diff 11c7aa0d Mon Jun 07 05:26:13 MDT 2021 Jan Kara <jack@suse.cz> rq-qos: fix missed wake-ups in rq_qos_throttle try two Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") tried to fix a problem that a process could be sleeping in rq_qos_wait() without anyone to wake it up. However the fix is not complete and the following can still happen: CPU1 (waiter1) CPU2 (waiter2) CPU3 (waker) rq_qos_wait() rq_qos_wait() acquire_inflight_cb() -> fails acquire_inflight_cb() -> fails completes IOs, inflight decreased prepare_to_wait_exclusive() prepare_to_wait_exclusive() has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers has_sleeper = !wq_has_single_sleeper() -> true io_schedule() io_schedule() Deadlock as now there's nobody to wakeup the two waiters. The logic automatically blocking when there are already sleepers is really subtle and the only way to make it work reliably is that we check whether there are some waiters in the queue when adding ourselves there. That way, we are guaranteed that at least the first process to enter the wait queue will recheck the waiting condition before going to sleep and thus guarantee forward progress. Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk> diff 2beaf328 Wed Mar 11 15:23:21 MDT 2020 Paul E. McKenney <paulmck@kernel.org> sched/core: Add function to sample state of locked-down task A running task's state can be sampled in a consistent manner (for example, for diagnostic purposes) simply by invoking smp_call_function_single() on its CPU, which may be obtained using task_cpu(), then having the IPI handler verify that the desired task is in fact still running. However, if the task is not running, this sampling can in theory be done immediately and directly. In practice, the task might start running at any time, including during the sampling period. Gaining a consistent sample of a not-running task therefore requires that something be done to lock down the target task's state. This commit therefore adds a try_invoke_on_locked_down_task() function that invokes a specified function if the specified task can be locked down, returning true if successful and if the specified function returns true. Otherwise this function simply returns false. Given that the function passed to try_invoke_on_nonrunning_task() might be invoked with a runqueue lock held, that function had better be quite lightweight. The function is passed the target task's task_struct pointer and the argument passed to try_invoke_on_locked_down_task(), allowing easy access to task state and to a location for further variables to be passed in and out. Note that the specified function will be called even if the specified task is currently running. The function can use ->on_rq and task_curr() to quickly and easily determine the task's state, and can return false if this state is not to the function's liking. The caller of the try_invoke_on_locked_down_task() would then see the false return value, and could take appropriate action, for example, trying again later or sending an IPI if matters are more urgent. It is expected that use cases such as the RCU CPU stall warning code will simply return false if the task is currently running. However, there are use cases involving nohz_full CPUs where the specified function might instead fall back to an alternative sampling scheme that relies on heavier synchronization (such as memory barriers) in the target task. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> [ paulmck: Apply feedback from Peter Zijlstra and Steven Rostedt. ] [ paulmck: Invoke if running to handle feedback from Mathieu Desnoyers. ] Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> diff 11a19c7b Fri Aug 25 10:13:55 MDT 2017 Tim Chen <tim.c.chen@linux.intel.com> sched/wait: Introduce wakeup boomark in wake_up_page_bit Now that we have added breaks in the wait queue scan and allow bookmark on scan position, we put this logic in the wake_up_page_bit function. We can have very long page wait list in large system where multiple pages share the same wait list. We break the wake up walk here to allow other cpus a chance to access the list, and not to disable the interrupts when traversing the list for too long. This reduces the interrupt and rescheduling latency, and excessive page wait queue lock hold time. [ v2: Remove bookmark_wake_function ] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 11a19c7b Fri Aug 25 10:13:55 MDT 2017 Tim Chen <tim.c.chen@linux.intel.com> sched/wait: Introduce wakeup boomark in wake_up_page_bit Now that we have added breaks in the wait queue scan and allow bookmark on scan position, we put this logic in the wake_up_page_bit function. We can have very long page wait list in large system where multiple pages share the same wait list. We break the wake up walk here to allow other cpus a chance to access the list, and not to disable the interrupts when traversing the list for too long. This reduces the interrupt and rescheduling latency, and excessive page wait queue lock hold time. [ v2: Remove bookmark_wake_function ] Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff dfd01f02 Sun Dec 13 14:11:16 MST 2015 Peter Zijlstra <peterz@infradead.org> sched/wait: Fix the signal handling fix Jan Stancek reported that I wrecked things for him by fixing things for Vladimir :/ His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which should not be possible, however my previous patch made this possible by unconditionally checking signal_pending(). We cannot use current->state as was done previously, because the instruction after the store to that variable it can be changed. We must instead pass the initial state along and use that. Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers") Reported-by: Jan Stancek <jstancek@redhat.com> Reported-by: Chris Mason <clm@fb.com> Tested-by: Jan Stancek <jstancek@redhat.com> Tested-by: Vladimir Murzin <vladimir.murzin@arm.com> Tested-by: Chris Mason <clm@fb.com> Reviewed-by: Paul Turner <pjt@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: tglx@linutronix.de Cc: Oleg Nesterov <oleg@redhat.com> Cc: hpa@zytor.com Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> diff 6b44f519 Sun Aug 24 11:12:27 MDT 2014 Scot Doyle <lkml14@scotdoyle.com> sched/wait: Document timeout corner case The timeout may elapse without 0 being returned, such as when waiting on an unused queue. Document this possibility. Signed-off-by: Scot Doyle <lkml14@scotdoyle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/alpine.LNX.2.11.1408241710070.6462@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@kernel.org> diff 9ffc93f2 Wed Mar 28 11:30:03 MDT 2012 David Howells <dhowells@redhat.com> Remove all #inclusions of asm/system.h Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com> |
/linux-master/mm/ | ||
H A D | filemap.c | diff 6758c112 Mon Apr 15 11:18:56 MDT 2024 Kairui Song <kasong@tencent.com> mm/filemap: optimize filemap folio adding Instead of doing multiple tree walks, do one optimism range check with lock hold, and exit if raced with another insertion. If a shadow exists, check it with a new xas_get_order helper before releasing the lock to avoid redundant tree walks for getting its order. Drop the lock and do the allocation only if a split is needed. In the best case, it only need to walk the tree once. If it needs to alloc and split, 3 walks are issued (One for first ranged conflict check and order retrieving, one for the second check after allocation, one for the insert after split). Testing with 4K pages, in an 8G cgroup, with 16G brd as block device: echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap --rw=randread --time_based \ --ramp_time=30s --runtime=5m --group_reporting Before: bw ( MiB/s): min= 1027, max= 3520, per=100.00%, avg=2445.02, stdev=18.90, samples=8691 iops : min=263001, max=901288, avg=625924.36, stdev=4837.28, samples=8691 After (+7.3%): bw ( MiB/s): min= 493, max= 3947, per=100.00%, avg=2625.56, stdev=25.74, samples=8651 iops : min=126454, max=1010681, avg=672142.61, stdev=6590.48, samples=8651 Test result with THP (do a THP randread then switch to 4K page in hope it issues a lot of splitting): echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap -thp=1 --readonly \ --rw=randread --time_based --ramp_time=30s --runtime=10m \ --group_reporting fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap \ --rw=randread --time_based --runtime=5s --group_reporting Before: bw ( KiB/s): min= 4141, max=14202, per=100.00%, avg=7935.51, stdev=96.85, samples=18976 iops : min= 1029, max= 3548, avg=1979.52, stdev=24.23, samples=18976· READ: bw=4545B/s (4545B/s), 4545B/s-4545B/s (4545B/s-4545B/s), io=64.0KiB (65.5kB), run=14419-14419msec After (+12.5%): bw ( KiB/s): min= 4611, max=15370, per=100.00%, avg=8928.74, stdev=105.17, samples=19146 iops : min= 1151, max= 3842, avg=2231.27, stdev=26.29, samples=19146 READ: bw=4635B/s (4635B/s), 4635B/s-4635B/s (4635B/s-4635B/s), io=64.0KiB (65.5kB), run=14137-14137msec The performance is better for both 4K (+7.5%) and THP (+12.5%) cached read. Link: https://lkml.kernel.org/r/20240415171857.19244-5-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff b2ebcf9d Mon Apr 15 11:18:54 MDT 2024 Kairui Song <kasong@tencent.com> mm/filemap: clean up hugetlb exclusion code __filemap_add_folio only has two callers, one never passes hugetlb folio and one always passes in hugetlb folio. So move the hugetlb related cgroup charging out of it to make the code cleaner. Link: https://lkml.kernel.org/r/20240415171857.19244-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff de60fd8d Mon Apr 15 11:18:53 MDT 2024 Kairui Song <kasong@tencent.com> mm/filemap: return early if failed to allocate memory for split Patch series "mm/filemap: optimize folio adding and splitting", v4. Currently, at least 3 tree walks are needed for filemap folio adding if the folio is previously evicted. One for getting the order of current slot, one for ranged conflict check, and one for another order retrieving. If a split is needed, more walks are needed. This series is trying to merge these walks, and speed up filemap_add_folio, I see a 7.5% - 12.5% performance gain for fio stress test. So instead of doing multiple tree walks, do one optimism range check with lock hold, and exit if raced with another insertion. If a shadow exists, check it with a new xas_get_order helper before releasing the lock to avoid redundant tree walks for getting its order. Drop the lock and do the allocation only if a split is needed. In the best case, it only need to walk the tree once. If it needs to alloc and split, 3 walks are issued (One for first ranged conflict check and order retrieving, one for the second check after allocation, one for the insert after split). Testing with 4K pages, in an 8G cgroup, with 16G brd as block device: echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap --rw=randread --time_based \ --ramp_time=30s --runtime=5m --group_reporting Before: bw ( MiB/s): min= 1027, max= 3520, per=100.00%, avg=2445.02, stdev=18.90, samples=8691 iops : min=263001, max=901288, avg=625924.36, stdev=4837.28, samples=8691 After (+7.3%): bw ( MiB/s): min= 493, max= 3947, per=100.00%, avg=2625.56, stdev=25.74, samples=8651 iops : min=126454, max=1010681, avg=672142.61, stdev=6590.48, samples=8651 Test result with THP (do a THP randread then switch to 4K page in hope it issues a lot of splitting): echo 3 > /proc/sys/vm/drop_caches fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap -thp=1 --readonly \ --rw=randread --time_based --ramp_time=30s --runtime=10m \ --group_reporting fio -name=cached --numjobs=16 --filename=/mnt/test.img \ --buffered=1 --ioengine=mmap \ --rw=randread --time_based --runtime=5s --group_reporting Before: bw ( KiB/s): min= 4141, max=14202, per=100.00%, avg=7935.51, stdev=96.85, samples=18976 iops : min= 1029, max= 3548, avg=1979.52, stdev=24.23, samples=18976· READ: bw=4545B/s (4545B/s), 4545B/s-4545B/s (4545B/s-4545B/s), io=64.0KiB (65.5kB), run=14419-14419msec After (+10.4%): bw ( KiB/s): min= 4611, max=15370, per=100.00%, avg=8928.74, stdev=105.17, samples=19146 iops : min= 1151, max= 3842, avg=2231.27, stdev=26.29, samples=19146 READ: bw=4635B/s (4635B/s), 4635B/s-4635B/s (4635B/s-4635B/s), io=64.0KiB (65.5kB), run=14137-14137msec The performance is better for both 4K (+7.5%) and THP (+12.5%) cached read. This patch (of 4): xas_split_alloc could fail with NOMEM, and in such case, it should abort early instead of keep going and fail the xas_split below. Link: https://lkml.kernel.org/r/20240416071722.45997-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20240415171857.19244-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20240415171857.19244-2-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff 5662400a Thu Jan 11 08:24:20 MST 2024 Matthew Wilcox (Oracle) <willy@infradead.org> mm: add pfn_swap_entry_folio() Patch series "mm: convert mm counter to take a folio", v3. Make sure all mm_counter() and mm_counter_file() callers have a folio, then convert mm counter functions to take a folio, which saves some compound_head() calls. This patch (of 10): Thanks to the compound_head() hidden inside PageLocked(), this saves a call to compound_head() over calling page_folio(pfn_swap_entry_to_page()) Link: https://lkml.kernel.org/r/20240111152429.3374566-1-willy@infradead.org Link: https://lkml.kernel.org/r/20240111152429.3374566-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff e8e17ee9 Thu Oct 12 11:04:28 MDT 2023 Lorenzo Stoakes <lstoakes@gmail.com> mm: drop the assumption that VM_SHARED always implies writable Patch series "permit write-sealed memfd read-only shared mappings", v4. The man page for fcntl() describing memfd file seals states the following about F_SEAL_WRITE:- Furthermore, trying to create new shared, writable memory-mappings via mmap(2) will also fail with EPERM. With emphasis on 'writable'. In turns out in fact that currently the kernel simply disallows all new shared memory mappings for a memfd with F_SEAL_WRITE applied, rendering this documentation inaccurate. This matters because users are therefore unable to obtain a shared mapping to a memfd after write sealing altogether, which limits their usefulness. This was reported in the discussion thread [1] originating from a bug report [2]. This is a product of both using the struct address_space->i_mmap_writable atomic counter to determine whether writing may be permitted, and the kernel adjusting this counter when any VM_SHARED mapping is performed and more generally implicitly assuming VM_SHARED implies writable. It seems sensible that we should only update this mapping if VM_MAYWRITE is specified, i.e. whether it is possible that this mapping could at any point be written to. If we do so then all we need to do to permit write seals to function as documented is to clear VM_MAYWRITE when mapping read-only. It turns out this functionality already exists for F_SEAL_FUTURE_WRITE - we can therefore simply adapt this logic to do the same for F_SEAL_WRITE. We then hit a chicken and egg situation in mmap_region() where the check for VM_MAYWRITE occurs before we are able to clear this flag. To work around this, perform this check after we invoke call_mmap(), with careful consideration of error paths. Thanks to Andy Lutomirski for the suggestion! [1]:https://lore.kernel.org/all/20230324133646.16101dfa666f253c4715d965@linux-foundation.org/ [2]:https://bugzilla.kernel.org/show_bug.cgi?id=217238 This patch (of 3): There is a general assumption that VMAs with the VM_SHARED flag set are writable. If the VM_MAYWRITE flag is not set, then this is simply not the case. Update those checks which affect the struct address_space->i_mmap_writable field to explicitly test for this by introducing [vma_]is_shared_maywrite() helper functions. This remains entirely conservative, as the lack of VM_MAYWRITE guarantees that the VMA cannot be written to. Link: https://lkml.kernel.org/r/cover.1697116581.git.lstoakes@gmail.com Link: https://lkml.kernel.org/r/d978aefefa83ec42d18dfa964ad180dbcde34795.1697116581.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Suggested-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff a08c7193 Tue Sep 26 01:20:17 MDT 2023 Sidhartha Kumar <sidhartha.kumar@oracle.com> mm/filemap: remove hugetlb special casing in filemap.c Remove special cased hugetlb handling code within the page cache by changing the granularity of ->index to the base page size rather than the huge page size. The motivation of this patch is to reduce complexity within the filemap code while also increasing performance by removing branches that are evaluated on every page cache lookup. To support the change in index, new wrappers for hugetlb page cache interactions are added. These wrappers perform the conversion to a linear index which is now expected by the page cache for huge pages. ========================= PERFORMANCE ====================================== Perf was used to check the performance differences after the patch. Overall the performance is similar to mainline with a very small larger overhead that occurs in __filemap_add_folio() and hugetlb_add_to_page_cache(). This is because of the larger overhead that occurs in xa_load() and xa_store() as the xarray is now using more entries to store hugetlb folios in the page cache. Timing aarch64 2MB Page Size 6.5-rc3 + this patch: [root@sidhakum-ol9-1 hugepages]# time fallocate -l 700GB test.txt real 1m49.568s user 0m0.000s sys 1m49.461s 6.5-rc3: [root]# time fallocate -l 700GB test.txt real 1m47.495s user 0m0.000s sys 1m47.370s 1GB Page Size 6.5-rc3 + this patch: [root@sidhakum-ol9-1 hugepages1G]# time fallocate -l 700GB test.txt real 1m47.024s user 0m0.000s sys 1m46.921s 6.5-rc3: [root@sidhakum-ol9-1 hugepages1G]# time fallocate -l 700GB test.txt real 1m44.551s user 0m0.000s sys 1m44.438s x86 2MB Page Size 6.5-rc3 + this patch: [root@sidhakum-ol9-2 hugepages]# time fallocate -l 100GB test.txt real 0m22.383s user 0m0.000s sys 0m22.255s 6.5-rc3: [opc@sidhakum-ol9-2 hugepages]$ time sudo fallocate -l 100GB /dev/hugepages/test.txt real 0m22.735s user 0m0.038s sys 0m22.567s 1GB Page Size 6.5-rc3 + this patch: [root@sidhakum-ol9-2 hugepages1GB]# time fallocate -l 100GB test.txt real 0m25.786s user 0m0.001s sys 0m25.589s 6.5-rc3: [root@sidhakum-ol9-2 hugepages1G]# time fallocate -l 100GB test.txt real 0m33.454s user 0m0.001s sys 0m33.193s aarch64: workload - fallocate a 700GB file backed by huge pages 6.5-rc3 + this patch: 2MB Page Size: --100.00%--__arm64_sys_fallocate ksys_fallocate vfs_fallocate hugetlbfs_fallocate | |--95.04%--__pi_clear_page | |--3.57%--clear_huge_page | | | |--2.63%--rcu_all_qs | | | --0.91%--__cond_resched | --0.67%--__cond_resched 0.17% 0.00% 0 fallocate [kernel.vmlinux] [k] hugetlb_add_to_page_cache 0.14% 0.10% 11 fallocate [kernel.vmlinux] [k] __filemap_add_folio 6.5-rc3 2MB Page Size: --100.00%--__arm64_sys_fallocate ksys_fallocate vfs_fallocate hugetlbfs_fallocate | |--94.91%--__pi_clear_page | |--4.11%--clear_huge_page | | | |--3.00%--rcu_all_qs | | | --1.10%--__cond_resched | --0.59%--__cond_resched 0.08% 0.01% 1 fallocate [kernel.kallsyms] [k] hugetlb_add_to_page_cache 0.05% 0.03% 3 fallocate [kernel.kallsyms] [k] __filemap_add_folio x86 workload - fallocate a 100GB file backed by huge pages 6.5-rc3 + this patch: 2MB Page Size: hugetlbfs_fallocate | --99.57%--clear_huge_page | --98.47%--clear_page_erms | --0.53%--asm_sysvec_apic_timer_interrupt 0.04% 0.04% 1 fallocate [kernel.kallsyms] [k] xa_load 0.04% 0.00% 0 fallocate [kernel.kallsyms] [k] hugetlb_add_to_page_cache 0.04% 0.00% 0 fallocate [kernel.kallsyms] [k] __filemap_add_folio 0.04% 0.00% 0 fallocate [kernel.kallsyms] [k] xas_store 6.5-rc3 2MB Page Size: --99.93%--__x64_sys_fallocate vfs_fallocate hugetlbfs_fallocate | --99.38%--clear_huge_page | |--98.40%--clear_page_erms | --0.59%--__cond_resched 0.03% 0.03% 1 fallocate [kernel.kallsyms] [k] __filemap_add_folio ========================= TESTING ====================================== This patch passes libhugetlbfs tests and LTP hugetlb tests ********** TEST SUMMARY * 2M * 32-bit 64-bit * Total testcases: 110 113 * Skipped: 0 0 * PASS: 107 113 * FAIL: 0 0 * Killed by signal: 3 0 * Bad configuration: 0 0 * Expected FAIL: 0 0 * Unexpected PASS: 0 0 * Test not present: 0 0 * Strange test result: 0 0 ********** Done executing testcases. LTP Version: 20220527-178-g2761a81c4 page migration was also tested using Mike Kravetz's test program.[8] [dan.carpenter@linaro.org: fix an NULL vs IS_ERR() bug] Link: https://lkml.kernel.org/r/1772c296-1417-486f-8eef-171af2192681@moroto.mountain Link: https://lkml.kernel.org/r/20230926192017.98183-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reported-and-tested-by: syzbot+c225dea486da4d5592bd@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c225dea486da4d5592bd Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff 87b11f86 Tue Jun 27 11:43:49 MDT 2023 Sidhartha Kumar <sidhartha.kumar@oracle.com> mm: increase usage of folio_next_index() helper Simplify code pattern of 'folio->index + folio_nr_pages(folio)' by using the existing helper folio_next_index(). Link: https://lkml.kernel.org/r/20230627174349.491803-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Suggested-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Christoph Hellwig <hch@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff 65747aaf Thu Jun 08 19:11:29 MDT 2023 Hugh Dickins <hughd@google.com> mm/filemap: allow pte_offset_map_lock() to fail filemap_map_pages() allow pte_offset_map_lock() to fail; and remove the pmd_devmap_trans_unstable() check from filemap_map_pmd(), which can safely return to filemap_map_pages() and let pte_offset_map_lock() discover that. Link: https://lkml.kernel.org/r/54607cf4-ddb6-7ef3-043-1d2de1a9a71@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> diff dd5b9d00 Wed Feb 08 11:18:17 MST 2023 David Howells <dhowells@redhat.com> mm: Pass info, not iter, into filemap_get_pages() filemap_get_pages() and a number of functions that it calls take an iterator to provide two things: the number of bytes to be got from the file specified and whether partially uptodate pages are allowed. Change these functions so that this information is passed in directly. This allows it to be called without having an iterator to hand. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> cc: Christoph Hellwig <hch@lst.de> cc: Matthew Wilcox <willy@infradead.org> cc: Al Viro <viro@zeniv.linux.org.uk> cc: David Hildenbrand <david@redhat.com> cc: John Hubbard <jhubbard@nvidia.com> cc: linux-mm@kvack.org cc: linux-block@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> diff 3720dd6d Tue Nov 01 11:53:22 MDT 2022 Vishal Moola (Oracle) <vishal.moola@gmail.com> filemap: convert replace_page_cache_page() to replace_page_cache_folio() Patch series "Removing the lru_cache_add() wrapper". This patchset replaces all calls of lru_cache_add() with the folio equivalent: folio_add_lru(). This is allows us to get rid of the wrapper The series passes xfstests and the userfaultfd selftests. This patch (of 5): Eliminates 7 calls to compound_head(). Link: https://lkml.kernel.org/r/20221101175326.13265-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20221101175326.13265-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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