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| author | Riccardo Mancini <rickyman7@gmail.com> | 2021-08-21 11:19:07 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2021-10-08 11:29:16 -0300 |
| commit | 73e40c9bd44ce91fd0fcee6f0a3480dcd97963b6 (patch) | |
| tree | 74b36a07d967076495775b59711111f8461d7179 /tools/lib | |
| parent | 47e7dd34a26def31af352df3a8281e7ff1bc345a (diff) | |
| download | linux-73e40c9bd44ce91fd0fcee6f0a3480dcd97963b6.tar.bz2 | |
libperf cpumap: Use binary search in perf_cpu_map__idx() as array are sorted
Since 7074674e7338863e ("perf cpumap: Maintain cpumaps ordered and
without dups") perf_cpu_map elements are sorted in ascending order.
This patch improves perf_cpu_map__idx() by using a binary search.
Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/f1543c15797169c21e8b205a4a6751159180580d.1629490974.git.rickyman7@gmail.com
[ Removed 'else' after if + return, declared variables where needed ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/perf/cpumap.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index 6d8e521c59e1..adaad3dddf6e 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -270,11 +270,19 @@ bool perf_cpu_map__empty(const struct perf_cpu_map *map) int perf_cpu_map__idx(struct perf_cpu_map *cpus, int cpu) { - int i; + int low = 0, high = cpus->nr; - for (i = 0; i < cpus->nr; ++i) { - if (cpus->map[i] == cpu) - return i; + while (low < high) { + int idx = (low + high) / 2, + cpu_at_idx = cpus->map[idx]; + + if (cpu_at_idx == cpu) + return idx; + + if (cpu_at_idx > cpu) + high = idx; + else + low = idx + 1; } return -1; |