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authorRiccardo Mancini <rickyman7@gmail.com>2021-08-21 11:19:07 +0200
committerArnaldo Carvalho de Melo <acme@redhat.com>2021-10-08 11:29:16 -0300
commit73e40c9bd44ce91fd0fcee6f0a3480dcd97963b6 (patch)
tree74b36a07d967076495775b59711111f8461d7179 /tools/lib
parent47e7dd34a26def31af352df3a8281e7ff1bc345a (diff)
downloadlinux-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.c16
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;