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

From: Leo Yan
Date: Sun Jul 11 2021 - 06:41:32 EST


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

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
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
--
2.25.1