diff options
| author | Namhyung Kim <namhyung@kernel.org> | 2023-03-13 21:48:22 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2023-03-14 12:32:59 +0100 |
| commit | 3ace2435bb93445e7713d69336011c46558a18af (patch) | |
| tree | a299647436aee8c470af3f6cb682a05dbad3981b /tools/perf/builtin-lock.c | |
| parent | perf build: Error if no libelf and NO_LIBELF isn't set (diff) | |
| download | linux-3ace2435bb93445e7713d69336011c46558a18af.tar.xz linux-3ace2435bb93445e7713d69336011c46558a18af.zip | |
perf lock contention: Track and show mmap_lock with address
Sometimes there are severe contentions on the mmap_lock and we want
see it in the -l/--lock-addr output. However it cannot symbolize
the mmap_lock because it's allocated dynamically without symbols.
Stephane and Hao gave me an idea separately to display mmap_lock by
following the current->mm pointer. I added a flag to mark mmap_lock
after comparing the lock address so that it can show them differently.
With this change it can show mmap_lock like below:
$ sudo ./perf lock con -abl -- sleep 10
contended total wait max wait avg wait address symbol
...
16344 312.30 ms 2.22 ms 19.11 us ffff8cc702595640
17686 310.08 ms 1.49 ms 17.53 us ffff8cc7025952c0
3 84.14 ms 45.79 ms 28.05 ms ffff8cc78114c478 mmap_lock
3557 76.80 ms 68.75 us 21.59 us ffff8cc77ca3af58
1 68.27 ms 68.27 ms 68.27 ms ffff8cda745dfd70
9 54.53 ms 7.96 ms 6.06 ms ffff8cc7642a48b8 mmap_lock
14629 44.01 ms 60.00 us 3.01 us ffff8cc7625f9ca0
3481 42.63 ms 140.71 us 12.24 us ffffffff937906ac vmap_area_lock
16194 38.73 ms 42.15 us 2.39 us ffff8cd397cbc560
11 38.44 ms 10.39 ms 3.49 ms ffff8ccd6d12fbb8 mmap_lock
1 5.43 ms 5.43 ms 5.43 ms ffff8cd70018f0d8
1674 5.38 ms 422.93 us 3.21 us ffffffff92e06080 tasklist_lock
581 4.51 ms 130.68 us 7.75 us ffff8cc9b1259058
5 3.52 ms 1.27 ms 703.23 us ffff8cc754510070
112 3.47 ms 56.47 us 31.02 us ffff8ccee38b3120
381 3.31 ms 73.44 us 8.69 us ffffffff93790690 purge_vmap_area_lock
255 3.19 ms 36.35 us 12.49 us ffff8d053ce30c80
Note that mmap_lock was renamed some time ago and it needs to support
old kernels with a different name 'mmap_sem'.
Suggested-by: Hao Luo <haoluo@google.com>
Suggested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230313204825.2665483-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/builtin-lock.c')
| -rw-r--r-- | tools/perf/builtin-lock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index 240d49a85524..1b0dc946fe85 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -1663,7 +1663,7 @@ static void print_contention_result(struct lock_contention *con) break; case LOCK_AGGR_ADDR: pr_info(" %016llx %s\n", (unsigned long long)st->addr, - st->name ? : ""); + (st->flags & LCD_F_MMAP_LOCK) ? "mmap_lock" : st->name); break; default: break; |