[PATCH v4 04/11] perf/x86: Add barrier after updating bts
From: Leo Yan <hidden>
Date: 2021-07-11 10:41:31
Also in:
linux-arm-kernel, lkml
Subsystem:
performance events subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Thomas Gleixner, Borislav Petkov, Dave Hansen
Add barrier wmb() to separate the AUX data store and aux_head store. Signed-off-by: Leo Yan <redacted> --- 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
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2.25.1