perf tools: Replace map->referenced & maps->removed_maps with map->refcnt

Use just reference counts, so that when no more hist_entry instances
references a map and the thread instance goes away by processing a
PERF_RECORD_EXIT, we can delete the maps.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-oym7lfhcc7ss6xpz44h7nbxs@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 32 insertions, 73 deletions

diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index f53d017c7c22..6f28d53d4e46 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -313,8 +313,7 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
                                 memset(&he->stat, 0, sizeof(he->stat));
                 }
 
-                if (he->ms.map)
-                        he->ms.map->referenced = true;
+                map__get(he->ms.map);
 
                 if (he->branch_info) {
                         /*
@@ -324,6 +323,7 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
                          */
                         he->branch_info = malloc(sizeof(*he->branch_info));
                         if (he->branch_info == NULL) {
+                                map__zput(he->ms.map);
                                 free(he->stat_acc);
                                 free(he);
                                 return NULL;
@@ -332,17 +332,13 @@ static struct hist_entry *hist_entry__new(struct hist_entry *template,
                         memcpy(he->branch_info, template->branch_info,
                                sizeof(*he->branch_info));
 
-                        if (he->branch_info->from.map)
-                                he->branch_info->from.map->referenced = true;
-                        if (he->branch_info->to.map)
-                                he->branch_info->to.map->referenced = true;
+                        map__get(he->branch_info->from.map);
+                        map__get(he->branch_info->to.map);
                 }
 
                 if (he->mem_info) {
-                        if (he->mem_info->iaddr.map)
-                                he->mem_info->iaddr.map->referenced = true;
-                        if (he->mem_info->daddr.map)
-                                he->mem_info->daddr.map->referenced = true;
+                        map__get(he->mem_info->iaddr.map);
+                        map__get(he->mem_info->daddr.map);
                 }
 
                 if (symbol_conf.use_callchain)
@@ -407,9 +403,8 @@ static struct hist_entry *hists__findnew_entry(struct hists *hists,
                          * the history counter to increment.
                          */
                         if (he->ms.map != entry->ms.map) {
-                                he->ms.map = entry->ms.map;
-                                if (he->ms.map)
-                                        he->ms.map->referenced = true;
+                                map__put(he->ms.map);
+                                he->ms.map = map__get(entry->ms.map);
                         }
                         goto out;
                 }
@@ -933,8 +928,20 @@ hist_entry__collapse(struct hist_entry *left, struct hist_entry *right)
 void hist_entry__delete(struct hist_entry *he)
 {
         thread__zput(he->thread);
-        zfree(&he->branch_info);
-        zfree(&he->mem_info);
+        map__zput(he->ms.map);
+
+        if (he->branch_info) {
+                map__zput(he->branch_info->from.map);
+                map__zput(he->branch_info->to.map);
+                zfree(&he->branch_info);
+        }
+
+        if (he->mem_info) {
+                map__zput(he->mem_info->iaddr.map);
+                map__zput(he->mem_info->daddr.map);
+                zfree(&he->mem_info);
+        }
+
         zfree(&he->stat_acc);
         free_srcline(he->srcline);
         free_callchain(he->callchain);
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 1241ab989cf5..b5a5e9c02437 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -137,7 +137,6 @@ void map__init(struct map *map, enum map_type type,
         map->unmap_ip = map__unmap_ip;
         RB_CLEAR_NODE(&map->rb_node);
         map->groups   = NULL;
-        map->referenced = false;
         map->erange_warned = false;
         atomic_set(&map->refcnt, 1);
 }
@@ -439,7 +438,6 @@ static void maps__init(struct maps *maps)
 {
         maps->entries = RB_ROOT;
         pthread_rwlock_init(&maps->lock, NULL);
-        INIT_LIST_HEAD(&maps->removed_maps);
 }
 
 void map_groups__init(struct map_groups *mg, struct machine *machine)
@@ -466,21 +464,10 @@ static void __maps__purge(struct maps *maps)
         }
 }
 
-static void __maps__purge_removed_maps(struct maps *maps)
-{
-        struct map *pos, *n;
-
-        list_for_each_entry_safe(pos, n, &maps->removed_maps, node) {
-                list_del_init(&pos->node);
-                map__put(pos);
-        }
-}
-
 static void maps__exit(struct maps *maps)
 {
         pthread_rwlock_wrlock(&maps->lock);
         __maps__purge(maps);
-        __maps__purge_removed_maps(maps);
         pthread_rwlock_unlock(&maps->lock);
 }
 
@@ -499,8 +486,6 @@ bool map_groups__empty(struct map_groups *mg)
         for (i = 0; i < MAP__NR_TYPES; ++i) {
                 if (maps__first(&mg->maps[i]))
                         return false;
-                if (!list_empty(&mg->maps[i].removed_maps))
-                        return false;
         }
 
         return true;
@@ -621,7 +606,7 @@ size_t __map_groups__fprintf_maps(struct map_groups *mg, enum map_type type,
         return printed += maps__fprintf(&mg->maps[type], fp);
 }
 
-static size_t map_groups__fprintf_maps(struct map_groups *mg, FILE *fp)
+size_t map_groups__fprintf(struct map_groups *mg, FILE *fp)
 {
         size_t printed = 0, i;
         for (i = 0; i < MAP__NR_TYPES; ++i)
@@ -629,39 +614,6 @@ static size_t map_groups__fprintf_maps(struct map_groups *mg, FILE *fp)
         return printed;
 }
 
-static size_t __map_groups__fprintf_removed_maps(struct map_groups *mg,
-                                                 enum map_type type, FILE *fp)
-{
-        struct map *pos;
-        size_t printed = 0;
-
-        list_for_each_entry(pos, &mg->maps[type].removed_maps, node) {
-                printed += fprintf(fp, "Map:");
-                printed += map__fprintf(pos, fp);
-                if (verbose > 1) {
-                        printed += dso__fprintf(pos->dso, type, fp);
-                        printed += fprintf(fp, "--\n");
-                }
-        }
-        return printed;
-}
-
-static size_t map_groups__fprintf_removed_maps(struct map_groups *mg,
-                                               FILE *fp)
-{
-        size_t printed = 0, i;
-        for (i = 0; i < MAP__NR_TYPES; ++i)
-                printed += __map_groups__fprintf_removed_maps(mg, i, fp);
-        return printed;
-}
-
-size_t map_groups__fprintf(struct map_groups *mg, FILE *fp)
-{
-        size_t printed = map_groups__fprintf_maps(mg, fp);
-        printed += fprintf(fp, "Removed maps:\n");
-        return printed + map_groups__fprintf_removed_maps(mg, fp);
-}
-
 static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
 {
         struct rb_root *root;
@@ -719,13 +671,7 @@ static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp
                                 map__fprintf(after, fp);
                 }
 put_map:
-                /*
-                 * If we have references, just move them to a separate list.
-                 */
-                if (pos->referenced)
-                        list_add_tail(&pos->node, &maps->removed_maps);
-                else
-                        map__put(pos);
+                map__put(pos);
 
                 if (err)
                         goto out;
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index b8df09d94aca..d73e687b224e 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -34,7 +34,6 @@ struct map {
         u64                     start;
         u64                     end;
         u8 /* enum map_type */  type;
-        bool                    referenced;
         bool                    erange_warned;
         u32                     priv;
         u32                     prot;
@@ -63,7 +62,6 @@ struct kmap {
 struct maps {
         struct rb_root   entries;
         pthread_rwlock_t lock;
-        struct list_head removed_maps;
 };
 
 struct map_groups {
@@ -161,6 +159,14 @@ static inline struct map *map__get(struct map *map)
 
 void map__put(struct map *map);
 
+static inline void __map__zput(struct map **map)
+{
+        map__put(*map);
+        *map = NULL;
+}
+
+#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);