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/util/annotate.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'tools/perf/util/annotate.h') diff --git a/tools/perf/util/annotate.h b/tools/perf/util/annotate.h index 1c6335b8333a..962780559176 100644 --- a/tools/perf/util/annotate.h +++ b/tools/perf/util/annotate.h @@ -271,8 +271,7 @@ struct annotated_source { struct sym_hist *histograms; }; -struct annotation { - struct mutex lock; +struct LOCKABLE annotation { u64 max_coverage; u64 start; u64 hit_cycles; @@ -298,9 +297,15 @@ struct annotation { struct annotated_source *src; }; -void annotation__init(struct annotation *notes); +static inline void annotation__init(struct annotation *notes __maybe_unused) +{ +} void annotation__exit(struct annotation *notes); +void annotation__lock(struct annotation *notes) EXCLUSIVE_LOCK_FUNCTION(*notes); +void annotation__unlock(struct annotation *notes) UNLOCK_FUNCTION(*notes); +bool annotation__trylock(struct annotation *notes) EXCLUSIVE_TRYLOCK_FUNCTION(true, *notes); + static inline int annotation__cycles_width(struct annotation *notes) { if (notes->have_cycles && notes->options->show_minmax_cycle) -- cgit