Messages in this thread Patch in this message | | | Date | Sun, 19 Mar 2023 20:38:04 -0700 | Subject | [PATCH v4 16/22] perf maps: Modify maps_by_name to hold a reference to a map | From | Ian Rogers <> |
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To make it clearer about the ownership of a reference count split the by-name case from the regular start-address sorted tree. Put the reference count when maps_by_name is freed, which requires moving a decrement to nr_maps in maps__remove. Add two missing map puts in maps__fixup_overlappings in the event maps__insert fails.
Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/util/maps.c | 30 ++++++++++++++++-------------- tools/perf/util/symbol.c | 21 +++++++++++++++++---- 2 files changed, 33 insertions(+), 18 deletions(-)
diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c index ffd4a4a64026..74e3133f5007 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -26,6 +26,9 @@ static void __maps__free_maps_by_name(struct maps *maps) /* * Free everything to try to do it from the rbtree in the next search */ + for (unsigned int i = 0; i < maps__nr_maps(maps); i++) + map__put(maps__maps_by_name(maps)[i]); + zfree(&maps->maps_by_name); maps->nr_maps_allocated = 0; } @@ -42,7 +45,7 @@ static int __maps__insert(struct maps *maps, struct map *map) return -ENOMEM; RB_CLEAR_NODE(&new_rb_node->rb_node); - new_rb_node->map = map; + new_rb_node->map = map__get(map); while (*p != NULL) { parent = *p; @@ -55,7 +58,6 @@ static int __maps__insert(struct maps *maps, struct map *map) rb_link_node(&new_rb_node->rb_node, parent, p); rb_insert_color(&new_rb_node->rb_node, maps__entries(maps)); - map__get(map); return 0; } @@ -100,7 +102,7 @@ int maps__insert(struct maps *maps, struct map *map) maps->maps_by_name = maps_by_name; maps->nr_maps_allocated = nr_allocate; } - maps__maps_by_name(maps)[maps__nr_maps(maps) - 1] = map; + maps__maps_by_name(maps)[maps__nr_maps(maps) - 1] = map__get(map); __maps__sort_by_name(maps); } out: @@ -126,9 +128,9 @@ void maps__remove(struct maps *maps, struct map *map) rb_node = maps__find_node(maps, map); assert(rb_node->map == map); __maps__remove(maps, rb_node); - --maps->nr_maps; if (maps__maps_by_name(maps)) __maps__free_maps_by_name(maps); + --maps->nr_maps; up_write(maps__lock(maps)); } @@ -136,6 +138,9 @@ static void __maps__purge(struct maps *maps) { struct map_rb_node *pos, *next; + if (maps__maps_by_name(maps)) + __maps__free_maps_by_name(maps); + maps__for_each_entry_safe(maps, pos, next) { rb_erase_init(&pos->rb_node, maps__entries(maps)); map__put(pos->map); @@ -293,7 +298,7 @@ int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp) } next = first; - while (next) { + while (next && !err) { struct map_rb_node *pos = rb_entry(next, struct map_rb_node, rb_node); next = rb_next(&pos->rb_node); @@ -331,8 +336,10 @@ int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp) before->end = map__start(map); err = __maps__insert(maps, before); - if (err) + if (err) { + map__put(before); goto put_map; + } if (verbose >= 2 && !use_browser) map__fprintf(before, fp); @@ -352,22 +359,17 @@ int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp) assert(map__map_ip(pos->map, map__end(map)) == map__map_ip(after, map__end(map))); err = __maps__insert(maps, after); - if (err) + if (err) { + map__put(after); goto put_map; - + } if (verbose >= 2 && !use_browser) map__fprintf(after, fp); map__put(after); } put_map: map__put(pos->map); - - if (err) - goto out; } - - err = 0; -out: up_write(maps__lock(maps)); return err; } diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 0431c328f4d6..1f4c23052a54 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -2049,10 +2049,23 @@ int dso__load(struct dso *dso, struct map *map) static int map__strcmp(const void *a, const void *b) { - const struct dso *dso_a = map__dso(*(const struct map **)a); - const struct dso *dso_b = map__dso(*(const struct map **)b); + const struct map *map_a = *(const struct map **)a; + const struct map *map_b = *(const struct map **)b; + const struct dso *dso_a = map__dso(map_a); + const struct dso *dso_b = map__dso(map_b); + int ret = strcmp(dso_a->short_name, dso_b->short_name); - return strcmp(dso_a->short_name, dso_b->short_name); + if (ret == 0 && map_a != map_b) { + /* + * Ensure distinct but name equal maps have an order in part to + * aid reference counting. + */ + ret = (int)map__start(map_a) - (int)map__start(map_b); + if (ret == 0) + ret = (int)((intptr_t)map_a - (intptr_t)map_b); + } + + return ret; } static int map__strcmp_name(const void *name, const void *b) @@ -2084,7 +2097,7 @@ static int map__groups__sort_by_name_from_rbtree(struct maps *maps) maps->nr_maps_allocated = maps__nr_maps(maps); maps__for_each_entry(maps, rb_node) - maps_by_name[i++] = rb_node->map; + maps_by_name[i++] = map__get(rb_node->map); __maps__sort_by_name(maps); -- 2.40.0.rc1.284.g88254d51c5-goog
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