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perf tools: Use atomic.h for the map_groups refcount

tip:perf/core tip-bot for Arnaldo Carvalho de Melo 1 participant 1 message May 20, 2015 perf events

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Commit-ID:  848cbd2562bb85953884be72b3bdbee0b2f32474
Gitweb:     http://git.kernel.org/tip/848cbd2562bb85953884be72b3bdbee0b2f32474
Author:     Arnaldo Carvalho de Melo <[email protected]>
AuthorDate: Fri, 15 May 2015 15:20:44 -0300
Committer:  Arnaldo Carvalho de Melo <[email protected]>
CommitDate: Fri, 15 May 2015 15:20:44 -0300

perf tools: Use atomic.h for the map_groups refcount

Now that we have atomic.h, we should convert all of the existing refcounts to use it.

Cc Adrian Hunter <[email protected]>
Cc Borislav Petkov <[email protected]>
Cc David Ahern <[email protected]>
Cc Don Zickus <[email protected]>
Cc Frederic Weisbecker <[email protected]>
Cc Jiri Olsa <[email protected]>
Cc Namhyung Kim <[email protected]>
Cc Stephane Eranian <[email protected]>
Link http://lkml.kernel.org/n/[email protected] open here
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
---
 tools/perf/tests/thread-mg-share.c | 12 ++++++------
 tools/perf/util/map.c              |  4 ++--
 tools/perf/util/map.h              |  6 ++++--
 3 files changed, 12 insertions(+), 10 deletions(-)
tools/perf/tests/thread-mg-share.c +6 -6
index c0ed56f..01fabb1 100644
@@ -43,7 +43,7 @@ int test__thread_mg_share(void)
 			leader && t1 && t2 && t3 && other);
 
 	mg = leader->mg;
-	TEST_ASSERT_EQUAL("wrong refcnt", mg->refcnt, 4);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 4);
 
 	/* test the map groups pointer is shared */
 	TEST_ASSERT_VAL("map groups don't match", mg == t1->mg);

@@ -71,25 +71,25 @@ int test__thread_mg_share(void)
 	machine__remove_thread(machine, other_leader);
 
 	other_mg = other->mg;
-	TEST_ASSERT_EQUAL("wrong refcnt", other_mg->refcnt, 2);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 2);
 
 	TEST_ASSERT_VAL("map groups don't match", other_mg == other_leader->mg);
 
 	/* release thread group */
 	thread__put(leader);
-	TEST_ASSERT_EQUAL("wrong refcnt", mg->refcnt, 3);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 3);
 
 	thread__put(t1);
-	TEST_ASSERT_EQUAL("wrong refcnt", mg->refcnt, 2);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 2);
 
 	thread__put(t2);
-	TEST_ASSERT_EQUAL("wrong refcnt", mg->refcnt, 1);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 1);
 
 	thread__put(t3);
 
 	/* release other group  */
 	thread__put(other_leader);
-	TEST_ASSERT_EQUAL("wrong refcnt", other_mg->refcnt, 1);
+	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 1);
 
 	thread__put(other);
tools/perf/util/map.c +2 -2
index cd0e335..2d20c5f 100644
@@ -426,7 +426,7 @@ void map_groups__init(struct map_groups *mg, struct machine *machine)
 		INIT_LIST_HEAD(&mg->removed_maps[i]);
 	}
 	mg->machine = machine;
-	mg->refcnt = 1;
+	atomic_set(&mg->refcnt, 1);
 }
 
 static void maps__delete(struct rb_root *maps)

@@ -494,7 +494,7 @@ void map_groups__delete(struct map_groups *mg)
 
 void map_groups__put(struct map_groups *mg)
 {
-	if (--mg->refcnt == 0)
+	if (mg && atomic_dec_and_test(&mg->refcnt))
 		map_groups__delete(mg);
 }
tools/perf/util/map.h +4 -2
index 4e0c729..7f39217 100644
@@ -1,6 +1,7 @@
 #ifndef __PERF_MAP_H
 #define __PERF_MAP_H
 
+#include <linux/atomic.h>
 #include <linux/compiler.h>
 #include <linux/list.h>
 #include <linux/rbtree.h>

@@ -61,7 +62,7 @@ struct map_groups {
 	struct rb_root	 maps[MAP__NR_TYPES];
 	struct list_head removed_maps[MAP__NR_TYPES];
 	struct machine	 *machine;
-	int		 refcnt;
+	atomic_t	 refcnt;
 };
 
 struct map_groups *map_groups__new(struct machine *machine);

@@ -70,7 +71,8 @@ bool map_groups__empty(struct map_groups *mg);
 
 static inline struct map_groups *map_groups__get(struct map_groups *mg)
 {
-	++mg->refcnt;
+	if (mg)
+		atomic_inc(&mg->refcnt);
 	return mg;
 }