Messages in this thread | | | From | Namhyung Kim <> | Date | Fri, 24 Jun 2022 09:40:05 -0700 | Subject | Re: [PATCHSET 0/7] perf lock: New lock contention tracepoints support (v4) |
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Ping! Any comments?
On Wed, Jun 15, 2022 at 9:32 AM Namhyung Kim <namhyung@kernel.org> wrote: > > Hello, > > Kernel v5.19 will have a new set of tracepoints to track lock > contentions for various lock types. Unlike tracepoints in LOCKDEP and > LOCK_STAT, it's hit only for contended locks and lock names are not > available. So it needs to collect stack traces and display the caller > function instead. > > Changes in v4) > * add Acked-by from Ian > * more comments on trace_lock_handler > * don't create stats in the contention_end handler > > Changes in v3) > * fix build error > * support data from different kernels/machines > * skip bad stat unless there's actual bad ones > > Changes in v2) > * add Acked-by from Ian > * print time with a unit for compact output > * add some comments (Ian) > * remove already applied patch > > This patchset merely adds support for the new tracepoints to the > existing perf lock commands. So there's no change to the user. Later > I'll add new a sub-command dedicated to the tracepoints to make use of > the additional information. > > Example output: > > $ sudo perf lock record -a sleep 3 > > $ perf lock report -F acquired,contended,avg_wait,wait_total > > Name acquired contended avg wait total wait > > update_blocked_a... 40 40 3.61 us 144.45 us > kernfs_fop_open+... 5 5 3.64 us 18.18 us > _nohz_idle_balance 3 3 2.65 us 7.95 us > tick_do_update_j... 1 1 6.04 us 6.04 us > ep_scan_ready_list 1 1 3.93 us 3.93 us > ... > > You can find the code in the 'perf/lock-contention-v4' branch at > > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git > > Thanks, > Namhyung > > > Namhyung Kim (7): > perf lock: Print wait times with unit > perf lock: Allow to use different kernel symbols > perf lock: Skip print_bad_events() if nothing bad > perf lock: Add lock contention tracepoints record support > perf lock: Handle lock contention tracepoints > perf record: Allow to specify max stack depth of fp callchain > perf lock: Look up callchain for the contended locks > > tools/perf/Documentation/perf-lock.txt | 7 + > tools/perf/Documentation/perf-record.txt | 5 + > tools/perf/builtin-lock.c | 426 ++++++++++++++++++++++- > tools/perf/util/callchain.c | 18 +- > 4 files changed, 434 insertions(+), 22 deletions(-) > > > base-commit: 9886142c7a2226439c1e3f7d9b69f9c7094c3ef6 > -- > 2.36.1.476.g0c4daa206d-goog >
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