[PATCH v4 04/11] perf/x86: Add barrier after updating bts

Add barrier wmb() to separate the AUX data store and aux_head store.

Signed-off-by: Leo Yan leo.yan@linaro.org --- arch/x86/events/intel/bts.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c index 6320d2cfd9d3..4a015d160bc5 100644 --- a/arch/x86/events/intel/bts.c +++ b/arch/x86/events/intel/bts.c @@ -209,6 +209,9 @@ static void bts_update(struct bts_ctx *bts) } else { local_set(&buf->data_size, head); } + + /* The WMB separates data store and aux_head store matches. */ + wmb(); }

static int