From 2e9f9d4a729f12b4bc3fa60406374327b1809abe Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 14 Jun 2023 21:07:15 -0700 Subject: perf annotation: Switch lock from a mutex to a sharded_mutex Remove the "struct mutex lock" variable from annotation that is allocated per symbol. This removes in the region of 40 bytes per symbol allocation. Use a sharded mutex where the number of shards is set to the number of CPUs. Assuming good hashing of the annotation (done based on the pointer), this means in order to contend there needs to be more threads than CPUs, which is not currently true in any perf command. Were contention an issue it is straightforward to increase the number of shards in the mutex. On my Debian/glibc based machine, this reduces the size of struct annotation from 136 bytes to 96 bytes, or nearly 30%. Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Andres Freund Cc: Mark Rutland Cc: Yuan Can Cc: Peter Zijlstra Cc: Adrian Hunter Cc: Arnaldo Carvalho de Melo Cc: Huacai Chen Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Alexander Shishkin Cc: Kan Liang Cc: Ingo Molnar Link: https://lore.kernel.org/r/20230615040715.2064350-2-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/builtin-top.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'tools/perf/builtin-top.c') diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index c363c04e16df..1baa2acb3ced 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -137,10 +137,10 @@ static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he) } notes = symbol__annotation(sym); - mutex_lock(¬es->lock); + annotation__lock(notes); if (!symbol__hists(sym, top->evlist->core.nr_entries)) { - mutex_unlock(¬es->lock); + annotation__unlock(notes); pr_err("Not enough memory for annotating '%s' symbol!\n", sym->name); sleep(1); @@ -156,7 +156,7 @@ static int perf_top__parse_source(struct perf_top *top, struct hist_entry *he) pr_err("Couldn't annotate %s: %s\n", sym->name, msg); } - mutex_unlock(¬es->lock); + annotation__unlock(notes); return err; } @@ -211,12 +211,12 @@ static void perf_top__record_precise_ip(struct perf_top *top, notes = symbol__annotation(sym); - if (!mutex_trylock(¬es->lock)) + if (!annotation__trylock(notes)) return; err = hist_entry__inc_addr_samples(he, sample, evsel, ip); - mutex_unlock(¬es->lock); + annotation__unlock(notes); if (unlikely(err)) { /* @@ -253,7 +253,7 @@ static void perf_top__show_details(struct perf_top *top) symbol = he->ms.sym; notes = symbol__annotation(symbol); - mutex_lock(¬es->lock); + annotation__lock(notes); symbol__calc_percent(symbol, evsel); @@ -274,7 +274,7 @@ static void perf_top__show_details(struct perf_top *top) if (more != 0) printf("%d lines not displayed, maybe increase display entries [e]\n", more); out_unlock: - mutex_unlock(¬es->lock); + annotation__unlock(notes); } static void perf_top__resort_hists(struct perf_top *t) -- cgit v1.2.3