perf map: Optimize maps__fixup_overlappings()

This function splits and removes overlapping areas.

Maps in tree are ordered by start address thus we could find first
overlap and stop if next map does not overlap.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/153365189407.435244.7234821822450484712.stgit@buzz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2 files changed, 26 insertions, 19 deletions

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 89ac5b5dc218..36d0763311ef 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -381,20 +381,6 @@ struct map *map__clone(struct map *from)
         return map;
 }
 
-int map__overlap(struct map *l, struct map *r)
-{
-        if (l->start > r->start) {
-                struct map *t = l;
-                l = r;
-                r = t;
-        }
-
-        if (l->end > r->start)
-                return 1;
-
-        return 0;
-}
-
 size_t map__fprintf(struct map *map, FILE *fp)
 {
         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
@@ -675,20 +661,42 @@ static void __map_groups__insert(struct map_groups *mg, struct map *map)
 static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
 {
         struct rb_root *root;
-        struct rb_node *next;
+        struct rb_node *next, *first;
         int err = 0;
 
         down_write(&maps->lock);
 
         root = &maps->entries;
-        next = rb_first(root);
 
+        /*
+         * Find first map where end > map->start.
+         * Same as find_vma() in kernel.
+         */
+        next = root->rb_node;
+        first = NULL;
+        while (next) {
+                struct map *pos = rb_entry(next, struct map, rb_node);
+
+                if (pos->end > map->start) {
+                        first = next;
+                        if (pos->start <= map->start)
+                                break;
+                        next = next->rb_left;
+                } else
+                        next = next->rb_right;
+        }
+
+        next = first;
         while (next) {
                 struct map *pos = rb_entry(next, struct map, rb_node);
                 next = rb_next(&pos->rb_node);
 
-                if (!map__overlap(pos, map))
-                        continue;
+                /*
+                 * Stop if current map starts after map->end.
+                 * Maps are ordered by start: next will not overlap for sure.
+                 */
+                if (pos->start >= map->end)
+                        break;
 
                 if (verbose >= 2) {
 
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 4cb90f242bed..e0f327b51e66 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -166,7 +166,6 @@ static inline void __map__zput(struct map **map)
 
 #define map__zput(map) __map__zput(&map)
 
-int map__overlap(struct map *l, struct map *r);
 size_t map__fprintf(struct map *map, FILE *fp);
 size_t map__fprintf_dsoname(struct map *map, FILE *fp);
 char *map__srcline(struct map *map, u64 addr, struct symbol *sym);