[1/4] perf mmap: Convert ACCESS_ONCE() to READ_ONCE()

Message ID 20171127103824.36526-2-mark.rutland@arm.com
State New
Headers show
Series
  • Final ACCESS_ONCE() cleanups for v4.15
Related show

Commit Message

Mark Rutland Nov. 27, 2017, 10:38 a.m.
Recently there was a treewide conversion of ACCESS_ONCE() to
{READ,WRITE}_ONCE(), but a new use was introduced concurrently by
commit:

  1695849735752d2a ("perf mmap: Move perf_mmap and methods to separate mmap.[ch] files")

Let's convert this over to READ_ONCE() so that we can remove the
ACCESS_ONCE() definitions in subsequent patches.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>

Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
 tools/perf/util/mmap.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.11.0

Patch

diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h
index efd78b827b05..3a5cb5a6e94a 100644
--- a/tools/perf/util/mmap.h
+++ b/tools/perf/util/mmap.h
@@ -70,7 +70,7 @@  void perf_mmap__read_catchup(struct perf_mmap *md);
 static inline u64 perf_mmap__read_head(struct perf_mmap *mm)
 {
 	struct perf_event_mmap_page *pc = mm->base;
-	u64 head = ACCESS_ONCE(pc->data_head);
+	u64 head = READ_ONCE(pc->data_head);
 	rmb();
 	return head;
 }