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authorArnaldo Carvalho de Melo <acme@redhat.com>2017-04-04 13:15:04 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-09-21 13:28:06 -0300
commit0a7c74eae307894c6c95316c382f118aef8481e8 (patch)
tree104338da632148c09cf33c436dad10eb608740da /tools/perf/util/symbol.c
parent6ae8eefc6c8fe050f057781b70a83262eb0a61ee (diff)
perf tools: Provide mutex wrappers for pthreads rwlocks
Andi reported a performance drop in single threaded perf tools such as 'perf script' due to the growing number of locks being put in place to allow for multithreaded tools, so wrap the POSIX threads rwlock routines with the names used for such kinds of locks in the Linux kernel and then allow for tools to ask for those locks to be used or not. I.e. a tool may have a multithreaded phase and then switch to single threaded, like the upcoming patches for the synthesizing of PERF_RECORD_{FORK,MMAP,etc} for pre-existing processes to then switch to single threaded mode in 'perf top'. The init routines will not be conditional, this way starting as single threaded to then move to multi threaded mode should be possible. Reported-by: Andi Kleen <ak@linux.intel.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/20170404161739.GH12903@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/symbol.c')
-rw-r--r--tools/perf/util/symbol.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 5909ee4c7ade..066e38aa4063 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -226,7 +226,7 @@ void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
struct maps *maps = &mg->maps[type];
struct map *next, *curr;
- pthread_rwlock_wrlock(&maps->lock);
+ down_write(&maps->lock);
curr = maps__first(maps);
if (curr == NULL)
@@ -246,7 +246,7 @@ void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
curr->end = ~0ULL;
out_unlock:
- pthread_rwlock_unlock(&maps->lock);
+ up_write(&maps->lock);
}
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
@@ -1671,7 +1671,7 @@ struct map *map_groups__find_by_name(struct map_groups *mg,
struct maps *maps = &mg->maps[type];
struct map *map;
- pthread_rwlock_rdlock(&maps->lock);
+ down_read(&maps->lock);
for (map = maps__first(maps); map; map = map__next(map)) {
if (map->dso && strcmp(map->dso->short_name, name) == 0)
@@ -1681,7 +1681,7 @@ struct map *map_groups__find_by_name(struct map_groups *mg,
map = NULL;
out_unlock:
- pthread_rwlock_unlock(&maps->lock);
+ up_read(&maps->lock);
return map;
}