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

On Wed, Jun 02, 2021 at 06:30:06PM +0800, Leo Yan wrote:

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

Signed-off-by: Leo Yan leo.yan@linaro.org

Acked-by: Peter Zijlstra (Intel) peterz@infradead.org

---

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