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30b331d2e3
To support live monitoring of kernel lock contention without BPF,
it should support something like below:
# perf lock record -a -o- sleep 1 | perf lock contention -i-
contended total wait max wait avg wait type caller
2 10.27 us 6.17 us 5.13 us spinlock load_balance+0xc03
1 5.29 us 5.29 us 5.29 us rwlock:W ep_scan_ready_list+0x54
1 4.12 us 4.12 us 4.12 us spinlock smpboot_thread_fn+0x116
1 3.28 us 3.28 us 3.28 us mutex pipe_read+0x50
To do that, it needs to handle HEAD_ATTR, HEADER_EVENT_UPDATE and
HEADER_TRACING_DATA which are generated only for the pipe mode.
And setting event handler also should be delayed until it gets the
event information.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221104051440.220989-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
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Please read the Documentation/process/changes.rst file, as it contains the
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