linux-kernel - [PATCH 1/1] perf/x86/intel: Fix SLM cache event list

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Date:	Tue, 21 Apr 2015 05:34:41 -0400
From:	kan.liang@...el.com
To:	a.p.zijlstra@...llo.nl
Cc:	andi@...stfloor.org, linux-kernel@...r.kernel.org,
	Kan Liang <kan.liang@...el.com>
Subject: [PATCH 1/1] perf/x86/intel: Fix SLM cache event list

From: Kan Liang <kan.liang@...el.com>

iTLB-load-misses and LLC-load-misses count wrong on SLM.

There is no ITLB.MISSES support on SLM. Event PAGE_WALKS.I_SIDE_WALK
should be used to count iTLB-load-misses. This event counts when an
instruction (I) page walk is completed or started. Since a page walk
implies a TLB miss, the number of TLB misses can be counted by counting
the number of pagewalks.

DMND_DATA_RD counts both demand and DCU prefetch data reads. However,
LLC-load-misses should only count demand read. There is no way to not
include prefetches with single counter on SLM. So the LLC-load-misses
support should be removed on SLM.

Signed-off-by: Kan Liang <kan.liang@...el.com>
---
 arch/x86/kernel/cpu/perf_event_intel.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 219d3fb..dab4257 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1134,7 +1134,7 @@ static __initconst const u64 slm_hw_cache_extra_regs
  [ C(LL  ) ] = {
 	[ C(OP_READ) ] = {
 		[ C(RESULT_ACCESS) ] = SLM_DMND_READ|SLM_LLC_ACCESS,
-		[ C(RESULT_MISS)   ] = SLM_DMND_READ|SLM_LLC_MISS,
+		[ C(RESULT_MISS)   ] = 0,
 	},
 	[ C(OP_WRITE) ] = {
 		[ C(RESULT_ACCESS) ] = SLM_DMND_WRITE|SLM_LLC_ACCESS,
@@ -1184,8 +1184,7 @@ static __initconst const u64 slm_hw_cache_event_ids
 	[ C(OP_READ) ] = {
 		/* OFFCORE_RESPONSE.ANY_DATA.LOCAL_CACHE */
 		[ C(RESULT_ACCESS) ] = 0x01b7,
-		/* OFFCORE_RESPONSE.ANY_DATA.ANY_LLC_MISS */
-		[ C(RESULT_MISS)   ] = 0x01b7,
+		[ C(RESULT_MISS)   ] = 0,
 	},
 	[ C(OP_WRITE) ] = {
 		/* OFFCORE_RESPONSE.ANY_RFO.LOCAL_CACHE */
@@ -1217,7 +1216,7 @@ static __initconst const u64 slm_hw_cache_event_ids
  [ C(ITLB) ] = {
 	[ C(OP_READ) ] = {
 		[ C(RESULT_ACCESS) ] = 0x00c0, /* INST_RETIRED.ANY_P */
-		[ C(RESULT_MISS)   ] = 0x0282, /* ITLB.MISSES */
+		[ C(RESULT_MISS)   ] = 0x40205, /* PAGE_WALKS.I_SIDE_WALKS */
 	},
 	[ C(OP_WRITE) ] = {
 		[ C(RESULT_ACCESS) ] = -1,
-- 
1.8.3.1

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