Re: [PATCH v5 5/9] perf auxtrace: Use WRITE_ONCE() for updating aux_tail
From: Arnaldo Carvalho de Melo <acme@kernel.org>
Date: 2021-08-09 20:00:04
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Em Mon, Aug 09, 2021 at 07:14:03PM +0800, Leo Yan escreveu:
Use WRITE_ONCE() for updating aux_tail, so can avoid unexpected memory behaviour.
Thanks, applied to perf/core. - Arnaldo
quoted hunk ↗ jump to hunk
Signed-off-by: Leo Yan <redacted> Acked-by: Adrian Hunter <adrian.hunter@intel.com> 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 cc1c1b9cec9c..79227b8864cd 100644 --- a/tools/perf/util/auxtrace.h +++ b/tools/perf/util/auxtrace.h@@ -480,7 +480,7 @@ 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(); #if BITS_PER_LONG == 64 || !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT) - pc->aux_tail = tail; + WRITE_ONCE(pc->aux_tail, tail); #else do { old_tail = __sync_val_compare_and_swap(&pc->aux_tail, 0, 0);-- 2.25.1
-- - Arnaldo