diff options
| author | Namhyung Kim <namhyung@kernel.org> | 2022-07-29 13:07:55 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-08-01 09:28:38 -0300 |
| commit | 407b36f69efbdccf341ccc5be6a366ec0795aa83 (patch) | |
| tree | 2f87ded5a067e430a1fac5d68d304c6e6ad3f721 /tools/perf/Documentation/perf-lock.txt | |
| parent | 77d54a2cd6086d1cc3cadd124084b5d0d40b713e (diff) | |
perf lock: Use BPF for lock contention analysis
Add -b/--use-bpf option to use BPF to collect lock contention stats.
For simplicity it now runs system-wide and requires C-c to stop.
Upcoming changes will add the usual filtering.
$ sudo perf lock con -b
^C
contended total wait max wait avg wait type caller
42 192.67 us 13.64 us 4.59 us spinlock queue_work_on+0x20
23 85.54 us 10.28 us 3.72 us spinlock worker_thread+0x14a
6 13.92 us 6.51 us 2.32 us mutex kernfs_iop_permission+0x30
3 11.59 us 10.04 us 3.86 us mutex kernfs_dop_revalidate+0x3c
1 7.52 us 7.52 us 7.52 us spinlock kthread+0x115
1 7.24 us 7.24 us 7.24 us rwlock:W sys_epoll_wait+0x148
2 7.08 us 3.99 us 3.54 us spinlock delayed_work_timer_fn+0x1b
1 6.41 us 6.41 us 6.41 us spinlock idle_balance+0xa06
2 2.50 us 1.83 us 1.25 us mutex kernfs_iop_lookup+0x2f
1 1.71 us 1.71 us 1.71 us mutex kernfs_iop_getattr+0x2c
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Blake Jones <blakejones@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20220729200756.666106-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation/perf-lock.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-lock.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt index 8f4e34f924d5..b88bb72c77d4 100644 --- a/tools/perf/Documentation/perf-lock.txt +++ b/tools/perf/Documentation/perf-lock.txt @@ -123,6 +123,11 @@ CONTENTION OPTIONS --threads:: Show per-thread lock contention stat +-b:: +--use-bpf:: + Use BPF program to collect lock contention stats instead of + using the input data. + SEE ALSO -------- |