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author | Song Liu <songliubraving@fb.com> | 2019-03-12 06:30:50 +0100 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-03-21 15:27:03 +0100 |
commit | 657ee5531903339b06697581532ed32d4762526e (patch) | |
tree | 72cf6f621fd22b79d154168245eed807c0e12b83 /drivers/nfc | |
parent | perf annotate: Enable annotation of BPF programs (diff) | |
download | linux-657ee5531903339b06697581532ed32d4762526e.tar.xz linux-657ee5531903339b06697581532ed32d4762526e.zip |
perf evlist: Introduce side band thread
This patch introduces side band thread that captures extended
information for events like PERF_RECORD_BPF_EVENT.
This new thread uses its own evlist that uses ring buffer with very low
watermark for lower latency.
To use side band thread, we need to:
1. add side band event(s) by calling perf_evlist__add_sb_event();
2. calls perf_evlist__start_sb_thread();
3. at the end of perf run, perf_evlist__stop_sb_thread().
In the next patch, we use this thread to handle PERF_RECORD_BPF_EVENT.
Committer notes:
Add fix by Jiri Olsa for when te sb_tread can't get started and then at
the end the stop_sb_thread() segfaults when joining the (non-existing)
thread.
That can happen when running 'perf top' or 'perf record' as a normal
user, for instance.
Further checks need to be done on top of this to more graciously handle
these possible failure scenarios.
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: http://lkml.kernel.org/r/20190312053051.2690567-15-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'drivers/nfc')
0 files changed, 0 insertions, 0 deletions