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SubjectRe: [RFC PATCH v1 01/37] libperf cpumap: improve idx function
Em Sat, Aug 21, 2021 at 11:19:07AM +0200, Riccardo Mancini escreveu:
> >From commit 7074674e7338863e ("perf cpumap: Maintain cpumaps ordered
> and without dups"), perf_cpu_map elements are sorted in ascending order.
>
> This patch improves the perf_cpu_map__idx function by using a binary
> search.

Thanks, applied.

- Arnaldo


> Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
> ---
> tools/lib/perf/cpumap.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c
> index ca0215047c326af4..fb633272be3aaed9 100644
> --- a/tools/lib/perf/cpumap.c
> +++ b/tools/lib/perf/cpumap.c
> @@ -265,11 +265,18 @@ 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, idx, cpu_at_idx;
>
> - for (i = 0; i < cpus->nr; ++i) {
> - if (cpus->map[i] == cpu)
> - return i;
> + while (low < high) {
> + idx = (low + high) / 2;
> + cpu_at_idx = cpus->map[idx];
> +
> + if (cpu_at_idx == cpu)
> + return idx;
> + else if (cpu_at_idx > cpu)
> + high = idx;
> + else
> + low = idx+1;
> }
>
> return -1;
> --
> 2.31.1

--

- Arnaldo

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