From: Ian Rogers Date: Tue, 22 Jul 2025 01:34:49 +0000 (-0700) Subject: perf pfm: Don't force loading of all PMUs X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=12d30725bf997ffd5baa849d4b20be86105fc070;p=users%2Fjedix%2Flinux-maple.git perf pfm: Don't force loading of all PMUs Force loading all PMUs adds significant cost because DRM and other PMUs are loaded, it should also not be required if the pmus__ functions are used. Tested by run perf test, in particular the pfm related tests. Also `perf list` is identical before and after. Before: $ time ./perf test pfm 54: Test libpfm4 support : 54.1: test of individual --pfm-events : Ok 54.2: test groups of --pfm-events : Ok 103: perf all libpfm4 events test : Ok real 0m8.933s user 0m1.824s sys 0m7.122s After: $ time ./perf test pfm 54: Test libpfm4 support : 54.1: test of individual --pfm-events : Ok 54.2: test groups of --pfm-events : Ok 103: perf all libpfm4 events test : Ok real 0m5.259s user 0m1.793s sys 0m3.570s Signed-off-by: Ian Rogers Tested-by: Namhyung Kim Link: https://lore.kernel.org/r/20250722013449.146233-1-irogers@google.com Signed-off-by: Namhyung Kim --- diff --git a/tools/perf/util/pfm.c b/tools/perf/util/pfm.c index 0dacc133ed396..e89395814e88b 100644 --- a/tools/perf/util/pfm.c +++ b/tools/perf/util/pfm.c @@ -47,10 +47,6 @@ int parse_libpfm_events_option(const struct option *opt, const char *str, p_orig = p = strdup(str); if (!p) return -1; - /* - * force loading of the PMU list - */ - perf_pmus__scan(NULL); for (q = p; strsep(&p, ",{}"); q = p) { sep = p ? str + (p - p_orig - 1) : "";