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SubjectRe: [PATCH 0/3] perf lock contention: Add BPF support (v1)
Em Fri, Jul 29, 2022 at 01:07:53PM -0700, Namhyung Kim escreveu:
> Hello,
>
> This patchset adds -b/--use-bpf option and others to use BPF to
> collect kernel lock contention stats. With this option it doesn't
> require a separate `perf lock record` step. Basic filtering on cpu
> (with -a or -C option) and on task (with -p and --tid option) is
> supported as usual.
>
> $ sudo perf lock con -a -b sleep 1
> 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
>
> It seems my system had some contentions on the workqueue spinlock and
> the kernfs mutex.
>
> The code is available at perf/lock-bpf-v1 branch in
>
> git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git

Thanks, applied.

- Arnaldo


> Thanks,
> Namhyung
>
>
> Namhyung Kim (3):
> perf lock: Pass machine pointer to is_lock_function()
> perf lock: Use BPF for lock contention analysis
> perf lock: Implement cpu and task filters for BPF
>
> tools/perf/Documentation/perf-lock.txt | 22 ++
> tools/perf/Makefile.perf | 2 +-
> tools/perf/builtin-lock.c | 226 ++++++++----------
> tools/perf/util/Build | 1 +
> tools/perf/util/bpf_lock_contention.c | 181 ++++++++++++++
> .../perf/util/bpf_skel/lock_contention.bpf.c | 170 +++++++++++++
> tools/perf/util/lock-contention.h | 140 +++++++++++
> 7 files changed, 614 insertions(+), 128 deletions(-)
> create mode 100644 tools/perf/util/bpf_lock_contention.c
> create mode 100644 tools/perf/util/bpf_skel/lock_contention.bpf.c
> create mode 100644 tools/perf/util/lock-contention.h
>
> --
> 2.37.1.455.g008518b4e5-goog

--

- Arnaldo

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