[patch] perf: remove l1-dcache-stores event for AMD

[patch] perf: remove l1-dcache-stores event for AMD

[Vince Weaver]

This is a long standing bug with the l1-dcache-stores generic event on
AMD machines.  My perf_event testsuite has been complaining about this
for years and I'm finally getting around to trying to get it fixed.

The data_cache_refills:system event does not make sense for l1-dcache-stores.
Maybe this was a typo and it was meant to be for l1-dcache-store-misses?

In any case, the values returned are nowhere near correct for l1-dcache-stores
and in fact the umask values for the event have completely changed with
fam15h so it makes even less sense than ever.  So just remove it.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>

diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 1cee5d2..05e76bf 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -18,7 +18,7 @@ static __initconst const u64 amd_hw_cache_event_ids
 		[ C(RESULT_MISS)   ] = 0x0141, /* Data Cache Misses          */
 	},
 	[ C(OP_WRITE) ] = {
-		[ C(RESULT_ACCESS) ] = 0x0142, /* Data Cache Refills :system */
+		[ C(RESULT_ACCESS) ] = 0,
 		[ C(RESULT_MISS)   ] = 0,
 	},
 	[ C(OP_PREFETCH) ] = {

[tip:perf/core] perf/x86/amd: Remove l1-dcache-stores event for AMD

[tip-bot for Vince Weaver]

Commit-ID:  9cc2617de5b9222abb39cd02e90d57dfea99c6d7
Gitweb:     http://git.kernel.org/tip/9cc2617de5b9222abb39cd02e90d57dfea99c6d7
Author:     Vince Weaver <vincent.weaver@maine.edu>
AuthorDate: Wed, 9 Dec 2015 11:34:45 -0500
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 6 Jan 2016 11:15:39 +0100

perf/x86/amd: Remove l1-dcache-stores event for AMD

This is a long standing bug with the l1-dcache-stores generic event on
AMD machines.  My perf_event testsuite has been complaining about this
for years and I'm finally getting around to trying to get it fixed.

The data_cache_refills:system event does not make sense for l1-dcache-stores.
Maybe this was a typo and it was meant to be for l1-dcache-store-misses?

In any case, the values returned are nowhere near correct for l1-dcache-stores
and in fact the umask values for the event have completely changed with
fam15h so it makes even less sense than ever.  So just remove it.

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1512091134350.24311@vincent-weaver-1.umelst.maine.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/cpu/perf_event_amd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 1cee5d2..05e76bf 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -18,7 +18,7 @@ static __initconst const u64 amd_hw_cache_event_ids
 		[ C(RESULT_MISS)   ] = 0x0141, /* Data Cache Misses          */
 	},
 	[ C(OP_WRITE) ] = {
-		[ C(RESULT_ACCESS) ] = 0x0142, /* Data Cache Refills :system */
+		[ C(RESULT_ACCESS) ] = 0,
 		[ C(RESULT_MISS)   ] = 0,
 	},
 	[ C(OP_PREFETCH) ] = {