From 392cf49ec54f0c7ba825ce9b04bf32bb85998135 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 4 Apr 2023 13:59:48 -0700 Subject: [PATCH] perf maps: Modify maps_by_name to hold a reference to a map 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 Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Bayduraev Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Shevchenko Cc: Darren Hart Cc: Davidlohr Bueso Cc: Dmitriy Vyukov Cc: Eric Dumazet Cc: German Gomez Cc: Hao Luo Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kajol Jain Cc: Kan Liang Cc: Leo Yan Cc: Madhavan Srinivasan Cc: Mark Rutland Cc: Masami Hiramatsu Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Riccardo Mancini Cc: Shunsuke Nakamura Cc: Song Liu Cc: Stephane Eranian Cc: Stephen Brennan Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Thomas Richter Cc: Yury Norov Link: https://lore.kernel.org/r/20230404205954.2245628-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- 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 0eee27e24c33b..5afed53ea0b4a 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 7282119c2990b..91ebf93e0c20b 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -2053,10 +2053,23 @@ out: 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) @@ -2088,7 +2101,7 @@ 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); -- 2.30.2