perf tools: Don't trow away old map slices not overlapped by new maps

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1267800842-22324-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 32 insertions, 3 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 21b92162282..9024fa1ff5c 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -183,8 +183,8 @@ struct thread *perf_session__findnew(struct perf_session *self, pid_t pid)
         return th;
 }
 
-static void map_groups__remove_overlappings(struct map_groups *self,
-                                            struct map *map)
+static int map_groups__fixup_overlappings(struct map_groups *self,
+                                          struct map *map)
 {
         struct rb_root *root = &self->maps[map->type];
         struct rb_node *next = rb_first(root);
@@ -209,7 +209,36 @@ static void map_groups__remove_overlappings(struct map_groups *self,
                  * list.
                  */
                 list_add_tail(&pos->node, &self->removed_maps[map->type]);
+                /*
+                 * Now check if we need to create new maps for areas not
+                 * overlapped by the new map:
+                 */
+                if (map->start > pos->start) {
+                        struct map *before = map__clone(pos);
+
+                        if (before == NULL)
+                                return -ENOMEM;
+
+                        before->end = map->start - 1;
+                        map_groups__insert(self, before);
+                        if (verbose >= 2)
+                                map__fprintf(before, stderr);
+                }
+
+                if (map->end < pos->end) {
+                        struct map *after = map__clone(pos);
+
+                        if (after == NULL)
+                                return -ENOMEM;
+
+                        after->start = map->end + 1;
+                        map_groups__insert(self, after);
+                        if (verbose >= 2)
+                                map__fprintf(after, stderr);
+                }
         }
+
+        return 0;
 }
 
 void maps__insert(struct rb_root *maps, struct map *map)
@@ -254,7 +283,7 @@ struct map *maps__find(struct rb_root *maps, u64 ip)
 
 void thread__insert_map(struct thread *self, struct map *map)
 {
-        map_groups__remove_overlappings(&self->mg, map);
+        map_groups__fixup_overlappings(&self->mg, map);
         map_groups__insert(&self->mg, map);
 }