Thread (28 messages) 28 messages, 4 authors, 2021-06-09
STALE1820d
Revisions (4)
  1. v2 current
  2. v3 [diff vs current]
  3. v4 [diff vs current]
  4. v5 [diff vs current]

[PATCH v2 7/8] perf auxtrace: Use WRITE_ONCE() for updating aux_tail

From: Leo Yan <hidden>
Date: 2021-06-02 10:30:57
Also in: linux-arm-kernel, lkml
Subsystem: performance events subsystem, the rest · Maintainers: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds

Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory
behaviour.

Signed-off-by: Leo Yan <redacted>
---
 tools/perf/util/auxtrace.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
index e625bc76cdde..abc4282f5272 100644
--- a/tools/perf/util/auxtrace.h
+++ b/tools/perf/util/auxtrace.h
@@ -458,7 +458,7 @@ static inline void auxtrace_mmap__write_tail(struct auxtrace_mmap *mm, u64 tail)
 
 	/* Ensure all reads are done before we write the tail out */
 	smp_mb();
-	pc->aux_tail = tail;
+	WRITE_ONCE(pc->aux_tail, tail);
 }
 
 int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
-- 
2.25.1
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help