perf pmu: Add YYDEBUG

YYDEBUG enables line numbers and other error helpers in the generated
pmu-bison.c. Conditionally enabled only for debug builds.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230911170559.4037734-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf pmu: Make the loading of formats lazy

The sysfs format files are loaded eagerly in a PMU. Add a flag so that
we create the format but only load the contents when necessary.

Reduce the size of the value in struct perf_pmu_format and avoid holes
so there is no additional space requirement.

For "perf stat -e cycles true" this reduces the number of openat calls
from 648 to 573 (about 12%). The benchmark pmu scan speed is improved
by roughly 5%.

Before:

$ perf bench internals pmu-scan
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 1061.100 usec (+- 9.965 usec)
Average PMU scanning took: 4725.300 usec (+- 260.599 usec)

After:

$ perf bench internals pmu-scan
Computing performance of sysfs PMU event scan for 100 times
Average core PMU scanning took: 989.170 usec (+- 6.873 usec)
Average PMU scanning took: 4520.960 usec (+- 251.272 usec)

Committer testing:

On a AMD Ryzen 5950x:

Before:

$ perf bench internals pmu-scan -i1000
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 563.466 usec (+- 1.008 usec)
Average PMU scanning took: 1619.174 usec (+- 23.627 usec)
$ perf stat -r5 perf bench internals pmu-scan -i1000
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 583.401 usec (+- 2.098 usec)
Average PMU scanning took: 1677.352 usec (+- 24.636 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 553.254 usec (+- 0.825 usec)
Average PMU scanning took: 1635.655 usec (+- 24.312 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 557.733 usec (+- 0.980 usec)
Average PMU scanning took: 1600.659 usec (+- 23.344 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 554.906 usec (+- 0.774 usec)
Average PMU scanning took: 1595.338 usec (+- 23.288 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 551.798 usec (+- 0.967 usec)
Average PMU scanning took: 1623.213 usec (+- 23.998 usec)

Performance counter stats for 'perf bench internals pmu-scan -i1000' (5 runs):

3276.82 msec task-clock:u # 0.990 CPUs utilized ( +- 0.82% )
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
1008 page-faults:u # 307.615 /sec ( +- 0.04% )
12049614778 cycles:u # 3.677 GHz ( +- 0.07% ) (83.34%)
117507478 stalled-cycles-frontend:u # 0.98% frontend cycles idle ( +- 0.33% ) (83.32%)
27106761 stalled-cycles-backend:u # 0.22% backend cycles idle ( +- 9.55% ) (83.36%)
33294953848 instructions:u # 2.76 insn per cycle
# 0.00 stalled cycles per insn ( +- 0.03% ) (83.31%)
6849825049 branches:u # 2.090 G/sec ( +- 0.03% ) (83.37%)
71533903 branch-misses:u # 1.04% of all branches ( +- 0.20% ) (83.30%)

3.3088 +- 0.0302 seconds time elapsed ( +- 0.91% )

$

After:

$ perf stat -r5 perf bench internals pmu-scan -i1000
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 550.702 usec (+- 0.958 usec)
Average PMU scanning took: 1566.577 usec (+- 22.747 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 548.315 usec (+- 0.555 usec)
Average PMU scanning took: 1565.499 usec (+- 22.760 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 548.073 usec (+- 0.555 usec)
Average PMU scanning took: 1586.097 usec (+- 23.299 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 561.184 usec (+- 2.709 usec)
Average PMU scanning took: 1567.153 usec (+- 22.548 usec)
# Running 'internals/pmu-scan' benchmark:
Computing performance of sysfs PMU event scan for 1000 times
Average core PMU scanning took: 546.987 usec (+- 0.553 usec)
Average PMU scanning took: 1562.814 usec (+- 22.729 usec)

Performance counter stats for 'perf bench internals pmu-scan -i1000' (5 runs):

3170.86 msec task-clock:u # 0.992 CPUs utilized ( +- 0.22% )
0 context-switches:u # 0.000 /sec
0 cpu-migrations:u # 0.000 /sec
1010 page-faults:u # 318.526 /sec ( +- 0.04% )
11890047674 cycles:u # 3.750 GHz ( +- 0.14% ) (83.27%)
119090499 stalled-cycles-frontend:u # 1.00% frontend cycles idle ( +- 0.46% ) (83.40%)
32502449 stalled-cycles-backend:u # 0.27% backend cycles idle ( +- 8.32% ) (83.30%)
33119141261 instructions:u # 2.79 insn per cycle
# 0.00 stalled cycles per insn ( +- 0.01% ) (83.37%)
6812816561 branches:u # 2.149 G/sec ( +- 0.01% ) (83.29%)
70157855 branch-misses:u # 1.03% of all branches ( +- 0.28% ) (83.38%)

3.19710 +- 0.00826 seconds time elapsed ( +- 0.26% )

$

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230824041330.266337-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf pmu: Reduce scope of perf_pmu_error()

Move declaration from header file to pmu.y and make static.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230823080828.1460376-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf pmu: Move perf_pmu__set_format to pmu.y

Avoid having the function in the C and header file, as it is only used
locally by pmu.y.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230823080828.1460376-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf build: Disable fewer bison warnings

If bison is version 3.8.2, reduce the number of bison C warnings
disabled. Earlier bison versions have all C warnings disabled. Avoid
implicit declarations of yylex by adding the declaration in the C
file. A header can't be included as a circular dependency would occur
due to the lexer using the bison defined tokens.

Committer notes:

Some recent versions of gcc and clang (noticed on Alpine Linux 3.17,
edge, clearlinux, fedora 37, etc.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Tom Rix <trix@redhat.com>
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230728064917.767761-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf pmu: Make parser reentrant

By default bison uses global state for compatibility with yacc. Make
the parser reentrant so that it may be used in asynchronous and
multithreaded situations.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230406065224.2553640-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf: Skip and warn on unknown format 'configN' attrs

If the kernel exposes a new perf_event_attr field in a format attr, perf
will return an error stating the specified PMU can't be found. For
example, a format attr with 'config3:0-63' causes an error as config3 is
unknown to perf. This causes a compatibility issue between a newer
kernel with older perf tool.

Before this change with a kernel adding 'config3' I get:

$ perf record -e arm_spe// -- true
event syntax error: 'arm_spe//'
\___ Cannot find PMU `arm_spe'. Missing kernel support?
Run 'perf list' for a list of valid events

Usage: perf record [<options>] [<command>]
or: perf record [<options>] -- <command> [<options>]

-e, --event <event> event selector. use 'perf list' to list
available events

After this change, I get:

$ perf record -e arm_spe// -- true
WARNING: 'arm_spe_0' format 'inv_event_filter' requires 'perf_event_attr::config3' which is not supported by this version of perf!
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.091 MB perf.data ]

To support unknown configN formats, rework the YACC implementation to
pass any config[0-9]+ format to perf_pmu__new_format() to handle with a
warning.

Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220914-arm-perf-tool-spe1-2-v2-v4-1-83c098e6212e@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf pmu: Remove perf_pmu_lex() needless declaration

It builds without it, perhaps with some older combination of flex/bison
we needed this, clean it up a bit removing this.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.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>
Link: https://lore.kernel.org/r/20220909044542.1087870-3-cuigaosheng1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Fix build with bison 2.3 and older.

The %name-prefix "prefix" syntax is not available on bison 2.3 and
older. Substitute with the -p "prefix" command-line option for
compatibility with older versions of bison.

This patch fixes this build error with older versions of bison.

CC util/sysfs.o
BISON util/pmu-bison.c
util/pmu.y:2.14-24: syntax error, unexpected string, expecting =
make: *** [util/pmu-bison.c] Error 1

Signed-off-by: Vinson Lee <vlee@twitter.com>
Tested-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org # 3.4+
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/1360792138-29186-1-git-send-email-vlee@twitter.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Use __maybe_used for unused variables

perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored

__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.

The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tools: Add perf pmu object to access pmu format definition

Adding pmu object which provides interface to pmu's sysfs
event format definition located at:
${sysfs_mount}/bus/event_source/devices/${pmu}/format

Following interface is exported:
struct perf_pmu* perf_pmu__find(char *name);
- this function returns pmu object, which is then
passed as a handle to other interface functions

int perf_pmu__config(struct perf_pmu *pmu, struct perf_event_attr *attr,
struct list_head *head_terms);
- this function configures perf_event_attr struct based
on pmu's format definitions and config terms data,
containined in head_terms list.

Parser generator is used to retrive the pmu's format definition.
The generated parser is part of the patch. Added makefile rule
'pmu-parser' to generate the parser code out of the bison/flex
sources.

Added builtin test 'Test perf pmu format parsing', which could
be run like:
perf test pmu

Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-errz96u1668gj9wlop1zhpht@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>