Messages in this thread | | | From | Namhyung Kim <> | Subject | [RFC/PATCH 0/3] perf lock contention: Track lock owner (v2) | Date | Mon, 6 Feb 2023 16:24:00 -0800 |
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Hello,
When there're many lock contentions in the system, people sometimes want to know who caused the contention, IOW who's the owner of the locks.
This patchset adds -o/--lock-owner option to track the owner info if it's available. Right now, it supports mutex and rwsem as they have the owner fields in themselves. Please see the patch 2 for the details.
Changes in v2) * fix missing callstacks * support old rwsem type with recent clang (>= 15.0)
The patch 1 is a fix for missing callstacks and the patch 2 is the main change. The patch 3 adds support for old kernels when compiler supports a recent builtin to check field type in a struct (Thanks to Hao).
Example output (for mutex only):
$ sudo ./perf lock con -abo -Y mutex -- ./perf bench sched pipe # Running 'sched/pipe' benchmark: # Executed 1000000 pipe operations between two processes
Total time: 4.910 [sec]
4.910435 usecs/op 203647 ops/sec contended total wait max wait avg wait pid owner
2 15.50 us 8.29 us 7.75 us 1582852 sched-pipe 7 7.20 us 2.47 us 1.03 us -1 Unknown 1 6.74 us 6.74 us 6.74 us 1582851 sched-pipe
You can get it from 'perf/lock-owner-v2' branch in
git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
Thanks, Namhyung
Namhyung Kim (3): perf lock contention: Fix to save callstack for the default modified perf lock contention: Add -o/--lock-owner option perf lock contention: Support old rw_semaphore type
tools/perf/Documentation/perf-lock.txt | 5 + tools/perf/builtin-lock.c | 52 +++++++++-- tools/perf/util/bpf_lock_contention.c | 1 + .../perf/util/bpf_skel/lock_contention.bpf.c | 91 ++++++++++++++++++- tools/perf/util/lock-contention.h | 1 + 5 files changed, 136 insertions(+), 14 deletions(-)
base-commit: 17f248aa8664ff5b3643491136283e73b5c18166 -- 2.39.1.519.gcb327c4b5f-goog
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