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2a5049b75d
The 'perf lock contention' program currently shows the caller of the locks
as __traceiter_contention_begin+0x??. This caller can be ignored, as it is
from the traceiter itself. Instead, it should show the real callers for
the locks.
When fiddling with the --stack-skip parameter, the actual callers for
the locks start to show up. However, just ignore the
__traceiter_contention_begin and the __traceiter_contention_end symbols
so the actual callers will show up.
Before this patch is applied:
sudo perf lock con -a -b -- sleep 3
contended total wait max wait avg wait type caller
8 2.33 s 2.28 s 291.18 ms rwlock:W __traceiter_contention_begin+0x44
4 2.33 s 2.28 s 582.35 ms rwlock:W __traceiter_contention_begin+0x44
7 140.30 ms 46.77 ms 20.04 ms rwlock:W __traceiter_contention_begin+0x44
2 63.35 ms 33.76 ms 31.68 ms mutex trace_contention_begin+0x84
2 46.74 ms 46.73 ms 23.37 ms rwlock:W __traceiter_contention_begin+0x44
1 13.54 us 13.54 us 13.54 us mutex trace_contention_begin+0x84
1 3.67 us 3.67 us 3.67 us rwsem:R __traceiter_contention_begin+0x44
Before this patch is applied - using --stack-skip 5
sudo perf lock con --stack-skip 5 -a -b -- sleep 3
contended total wait max wait avg wait type caller
2 2.24 s 2.24 s 1.12 s rwlock:W do_epoll_wait+0x5a0
4 1.65 s 824.21 ms 412.08 ms rwlock:W do_exit+0x338
2 824.35 ms 824.29 ms 412.17 ms spinlock get_signal+0x108
2 824.14 ms 824.14 ms 412.07 ms rwlock:W release_task+0x68
1 25.22 ms 25.22 ms 25.22 ms mutex cgroup_kn_lock_live+0x58
1 24.71 us 24.71 us 24.71 us spinlock do_exit+0x44
1 22.04 us 22.04 us 22.04 us rwsem:R lock_mm_and_find_vma+0xb0
After this patch is applied:
sudo ./perf lock con -a -b -- sleep 3
contended total wait max wait avg wait type caller
4 4.13 s 2.07 s 1.03 s rwlock:W release_task+0x68
2 2.07 s 2.07 s 1.03 s rwlock:R mm_update_next_owner+0x50
2 2.07 s 2.07 s 1.03 s rwlock:W do_exit+0x338
1 41.56 ms 41.56 ms 41.56 ms mutex cgroup_kn_lock_live+0x58
2 36.12 us 18.83 us 18.06 us rwlock:W do_exit+0x338
Signed-off-by: Anne Macedo <retpolanne@posteo.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
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: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240319143629.3422590-1-retpolanne@posteo.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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| .. | ||
| arch | ||
| bench | ||
| dlfilters | ||
| Documentation | ||
| include/perf | ||
| jvmti | ||
| pmu-events | ||
| python | ||
| scripts | ||
| tests | ||
| trace | ||
| ui | ||
| util | ||
| .gitignore | ||
| Build | ||
| builtin-annotate.c | ||
| builtin-bench.c | ||
| builtin-buildid-cache.c | ||
| builtin-buildid-list.c | ||
| builtin-c2c.c | ||
| builtin-config.c | ||
| builtin-daemon.c | ||
| builtin-data.c | ||
| builtin-diff.c | ||
| builtin-evlist.c | ||
| builtin-ftrace.c | ||
| builtin-help.c | ||
| builtin-inject.c | ||
| builtin-kallsyms.c | ||
| builtin-kmem.c | ||
| builtin-kvm.c | ||
| builtin-kwork.c | ||
| builtin-list.c | ||
| builtin-lock.c | ||
| builtin-mem.c | ||
| builtin-probe.c | ||
| builtin-record.c | ||
| builtin-report.c | ||
| builtin-sched.c | ||
| builtin-script.c | ||
| builtin-stat.c | ||
| builtin-timechart.c | ||
| builtin-top.c | ||
| builtin-trace.c | ||
| builtin-version.c | ||
| builtin.h | ||
| check-headers.sh | ||
| command-list.txt | ||
| CREDITS | ||
| design.txt | ||
| Makefile | ||
| Makefile.config | ||
| Makefile.perf | ||
| MANIFEST | ||
| perf-archive.sh | ||
| perf-completion.sh | ||
| perf-iostat.sh | ||
| perf-read-vdso.c | ||
| perf-sys.h | ||
| perf.c | ||
| perf.h | ||