diff options
author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-13 16:33:33 -0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-11-18 11:21:32 -0300 |
commit | 1ae14516cba032a83b561144d3d48fd381584c0c (patch) | |
tree | 8b6528f923d4a15536958035444ced4c8c0e3512 /tools/perf | |
parent | c5c584d2dbb0883f1e6f61872964a4a3a35a2017 (diff) | |
download | linux-1ae14516cba032a83b561144d3d48fd381584c0c.tar.bz2 |
perf map_groups: Add a front end cache for map lookups by name
Lets see if it helps:
First look at the probeable lines for the function that does lookups by
name in a map_groups struct:
# perf probe -x ~/bin/perf -L map_groups__find_by_name
<map_groups__find_by_name@/home/acme/git/perf/tools/perf/util/symbol.c:0>
0 struct map *map_groups__find_by_name(struct map_groups *mg, const char *name)
1 {
2 struct maps *maps = &mg->maps;
struct map *map;
5 down_read(&maps->lock);
7 if (mg->last_search_by_name && strcmp(mg->last_search_by_name->dso->short_name, name) == 0) {
8 map = mg->last_search_by_name;
9 goto out_unlock;
}
12 maps__for_each_entry(maps, map)
13 if (strcmp(map->dso->short_name, name) == 0) {
14 mg->last_search_by_name = map;
15 goto out_unlock;
}
18 map = NULL;
out_unlock:
21 up_read(&maps->lock);
22 return map;
23 }
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, bool vmlinux_allocated)
#
Now add a probe to the place where we reuse the last search:
# perf probe -x ~/bin/perf map_groups__find_by_name:8
Added new event:
probe_perf:map_groups__find_by_name (on map_groups__find_by_name:8 in /home/acme/bin/perf)
You can now use it in all perf tools, such as:
perf record -e probe_perf:map_groups__find_by_name -aR sleep 1
#
Now lets do a system wide 'perf stat' counting those events:
# perf stat -e probe_perf:*
Leave it running and lets do a 'perf top', then, after a while, stop the
'perf stat':
# perf stat -e probe_perf:*
^C
Performance counter stats for 'system wide':
3,603 probe_perf:map_groups__find_by_name
44.565253139 seconds time elapsed
#
yeah, good to have.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-tcz37g3nxv3tvxw3q90vga3p@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf')
-rw-r--r-- | tools/perf/util/map.c | 9 | ||||
-rw-r--r-- | tools/perf/util/map_groups.h | 6 | ||||
-rw-r--r-- | tools/perf/util/symbol.c | 9 |
3 files changed, 19 insertions, 5 deletions
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c index 49e353eaa337..d0899df77baa 100644 --- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -572,6 +572,7 @@ void map_groups__init(struct map_groups *mg, struct machine *machine) { maps__init(&mg->maps); mg->machine = machine; + mg->last_search_by_name = NULL; refcount_set(&mg->refcnt, 1); } @@ -580,6 +581,14 @@ void map_groups__insert(struct map_groups *mg, struct map *map) maps__insert(&mg->maps, map); } +void map_groups__remove(struct map_groups *mg, struct map *map) +{ + if (mg->last_search_by_name == map) + mg->last_search_by_name = NULL; + + maps__remove(&mg->maps, map); +} + static void __maps__purge(struct maps *maps) { struct map *pos, *next; diff --git a/tools/perf/util/map_groups.h b/tools/perf/util/map_groups.h index 26fc68bd4f60..f2a3158572eb 100644 --- a/tools/perf/util/map_groups.h +++ b/tools/perf/util/map_groups.h @@ -36,6 +36,7 @@ struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, st struct map_groups { struct maps maps; struct machine *machine; + struct map *last_search_by_name; refcount_t refcnt; #ifdef HAVE_LIBUNWIND_SUPPORT void *addr_space; @@ -70,10 +71,7 @@ size_t map_groups__fprintf(struct map_groups *mg, FILE *fp); void map_groups__insert(struct map_groups *mg, struct map *map); -static inline void map_groups__remove(struct map_groups *mg, struct map *map) -{ - maps__remove(&mg->maps, map); -} +void map_groups__remove(struct map_groups *mg, struct map *map); static inline struct map *map_groups__find(struct map_groups *mg, u64 addr) { diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 0fb9bd8bcf0d..b146d87176e7 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1767,9 +1767,16 @@ struct map *map_groups__find_by_name(struct map_groups *mg, const char *name) down_read(&maps->lock); + if (mg->last_search_by_name && strcmp(mg->last_search_by_name->dso->short_name, name) == 0) { + map = mg->last_search_by_name; + goto out_unlock; + } + maps__for_each_entry(maps, map) - if (strcmp(map->dso->short_name, name) == 0) + if (strcmp(map->dso->short_name, name) == 0) { + mg->last_search_by_name = map; goto out_unlock; + } map = NULL; |