2015-04-21 16:46:35

by Liang, Kan

[permalink] [raw]
Subject: [PATCH 1/1] perf/x86/intel: Fix SLM cache event list

From: Kan Liang <[email protected]>

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 <[email protected]>
---
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


Subject: [tip:perf/urgent] perf/x86/intel: Fix SLM cache event list

Commit-ID: 6d374056354a742eed4d0050498101e56e794c4b
Gitweb: http://git.kernel.org/tip/6d374056354a742eed4d0050498101e56e794c4b
Author: Kan Liang <[email protected]>
AuthorDate: Tue, 21 Apr 2015 05:34:41 -0400
Committer: Ingo Molnar <[email protected]>
CommitDate: Fri, 8 May 2015 11:59:41 +0200

perf/x86/intel: Fix SLM cache event list

iTLB-load-misses and LLC-load-misses count incorrectly 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 reads. There is no way to not
include prefetches with a single counter on SLM. So the LLC-load-misses
support should be removed on SLM.

Signed-off-by: Kan Liang <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
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 960e85d..3998131 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,