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| author | Namhyung Kim <namhyung@kernel.org> | 2024-08-29 23:51:49 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-08-30 09:57:47 -0300 |
| commit | 05a5dd1dfd8fdeee6498875c2d78d4385d627bd6 (patch) | |
| tree | 17b8cff0110711636b4f320ec731f6b1878c36a0 /tools/perf | |
| parent | 10d6c57c824e21b4cf8eda9491caea06edac9fd7 (diff) | |
| download | lwn-05a5dd1dfd8fdeee6498875c2d78d4385d627bd6.tar.gz lwn-05a5dd1dfd8fdeee6498875c2d78d4385d627bd6.zip | |
perf lock contention: Simplify spinlock check
The LCB_F_SPIN bit is used for spinlock, rwlock and optimistic spinning
in mutex. In get_tstamp_elem() it needs to check spinlock and rwlock
only. As mutex sets the LCB_F_MUTEX, it can check those two bits and
reduce the number of operations.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20240830065150.1758962-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/util/bpf_skel/lock_contention.bpf.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c index e8a6f6463019..4b7237e178bd 100644 --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c @@ -323,8 +323,7 @@ static inline struct tstamp_data *get_tstamp_elem(__u32 flags) struct tstamp_data *pelem; /* Use per-cpu array map for spinlock and rwlock */ - if (flags == (LCB_F_SPIN | LCB_F_READ) || flags == LCB_F_SPIN || - flags == (LCB_F_SPIN | LCB_F_WRITE)) { + if ((flags & (LCB_F_SPIN | LCB_F_MUTEX)) == LCB_F_SPIN) { __u32 idx = 0; pelem = bpf_map_lookup_elem(&tstamp_cpu, &idx); |