From bfb946753550d8d5f5bd5a156e4413c3df359faa Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 5 Dec 2024 20:40:35 -0800 Subject: [PATCH] libperf cpumap: Grow array of read CPUs in smaller increments Instead of growing the array by 2048, grow by the larger of the current range or 16. As ranges are typical for things like the online CPUs this will mean a single allocation happens. While uncore CPU maps will grow 16 at a time which is a value that is generous except say on large servers. Reviewed-by: Leo Yan Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ben Gainey Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Kan Liang Cc: Kyle Meyer Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20241206044035.1062032-9-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/perf/cpumap.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index 36f6579b3006..fcc47214062a 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -213,7 +213,7 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) goto invalid; if (nr_cpus == max_entries) { - max_entries += MAX_NR_CPUS; + max_entries += max(end_cpu - start_cpu + 1, 16UL); tmp = realloc(tmp_cpus, max_entries * sizeof(struct perf_cpu)); if (tmp == NULL) goto invalid; @@ -227,14 +227,15 @@ struct perf_cpu_map *perf_cpu_map__new(const char *cpu_list) cpu_list = p; } - if (nr_cpus > 0) + if (nr_cpus > 0) { cpus = cpu_map__trim_new(nr_cpus, tmp_cpus); - else if (*cpu_list != '\0') { + } else if (*cpu_list != '\0') { pr_warning("Unexpected characters at end of cpu list ('%s'), using online CPUs.", cpu_list); cpus = perf_cpu_map__new_online_cpus(); - } else + } else { cpus = perf_cpu_map__new_any_cpu(); + } invalid: free(tmp_cpus); out: -- 2.50.1