[PATCH] perf c2c: Fix remote HITM detection for Skylake

[PATCH] perf c2c: Fix remote HITM detection for Skylake

[Jiri Olsa]

Skylake introduced new mem_remote bit in union perf_mem_data_src [1].
It applies to any other memory level to express Remote unknown level,
as is reported by Skylake.

Adding this extra check to c2c_decode_stats to properly decode
remote HITMs on Skylake.

[1] http://lkml.kernel.org/r/20170816222156.19953-4-andi@firstfloor.org

Cc: Joe Mario <jmario@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/util/mem-events.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index ced4f3fff035..28afe5fa84d6 100644
--- a/tools/perf/util/mem-events.c
+++ b/tools/perf/util/mem-events.c
@@ -316,6 +316,11 @@ int c2c_decode_stats(struct c2c_stats *stats, struct mem_info *mi)
 	u64 lvl    = data_src->mem_lvl;
 	u64 snoop  = data_src->mem_snoop;
 	u64 lock   = data_src->mem_lock;
+	/*
+	 * Skylake might report unknown remote level via this
+	 * bit, consider it when evaluating remote HITMs.
+	 */
+	bool mrem  = data_src->mem_remote;
 	int err = 0;
 
 #define HITM_INC(__f)		\
@@ -361,7 +366,8 @@ do {				\
 			}
 
 			if ((lvl & P(LVL, REM_RAM1)) ||
-			    (lvl & P(LVL, REM_RAM2))) {
+			    (lvl & P(LVL, REM_RAM2)) ||
+			     mrem) {
 				stats->rmt_dram++;
 				if (snoop & P(SNOOP, HIT))
 					stats->ld_shared++;
@@ -371,7 +377,8 @@ do {				\
 		}
 
 		if ((lvl & P(LVL, REM_CCE1)) ||
-		    (lvl & P(LVL, REM_CCE2))) {
+		    (lvl & P(LVL, REM_CCE2)) ||
+		     mrem) {
 			if (snoop & P(SNOOP, HIT))
 				stats->rmt_hit++;
 			else if (snoop & P(SNOOP, HITM))
-- 
2.9.5

Re: [PATCH] perf c2c: Fix remote HITM detection for Skylake

[Andi Kleen]

On Thu, Aug 24, 2017 at 10:57:32AM +0200, Jiri Olsa wrote:
> Skylake introduced new mem_remote bit in union perf_mem_data_src [1].
> It applies to any other memory level to express Remote unknown level,
> as is reported by Skylake.
> 
> Adding this extra check to c2c_decode_stats to properly decode
> remote HITMs on Skylake.

Acked-by: Andi Kleen <ak@linux.intel.com>

-Andi

Re: [PATCH] perf c2c: Fix remote HITM detection for Skylake

[Arnaldo Carvalho de Melo]

Em Thu, Aug 24, 2017 at 02:45:07PM -0700, Andi Kleen escreveu:
> On Thu, Aug 24, 2017 at 10:57:32AM +0200, Jiri Olsa wrote:
> > Skylake introduced new mem_remote bit in union perf_mem_data_src [1].
> > It applies to any other memory level to express Remote unknown level,
> > as is reported by Skylake.
> > 
> > Adding this extra check to c2c_decode_stats to properly decode
> > remote HITMs on Skylake.
> 
> Acked-by: Andi Kleen <ak@linux.intel.com>

Thanks, applied.

- Arnaldo

[tip:perf/core] perf c2c: Fix remote HITM detection for Skylake

[tip-bot for Jiri Olsa]

Commit-ID:  12c15302dd4b768105d4b7a487ed4858ccab94fc
Gitweb:     http://git.kernel.org/tip/12c15302dd4b768105d4b7a487ed4858ccab94fc
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Thu, 24 Aug 2017 10:57:32 +0200
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 28 Aug 2017 11:05:10 -0300

perf c2c: Fix remote HITM detection for Skylake

Skylake introduced new mem_remote bit in union perf_mem_data_src [1].
It applies to any other memory level to express Remote unknown level, as
is reported by Skylake.

Adding this extra check to c2c_decode_stats to properly decode remote
HITMs on Skylake.

[1] http://lkml.kernel.org/r/20170816222156.19953-4-andi@firstfloor.org

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20170824085732.28481-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/mem-events.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index ced4f3f..28afe5f 100644
--- a/tools/perf/util/mem-events.c
+++ b/tools/perf/util/mem-events.c
@@ -316,6 +316,11 @@ int c2c_decode_stats(struct c2c_stats *stats, struct mem_info *mi)
 	u64 lvl    = data_src->mem_lvl;
 	u64 snoop  = data_src->mem_snoop;
 	u64 lock   = data_src->mem_lock;
+	/*
+	 * Skylake might report unknown remote level via this
+	 * bit, consider it when evaluating remote HITMs.
+	 */
+	bool mrem  = data_src->mem_remote;
 	int err = 0;
 
 #define HITM_INC(__f)		\
@@ -361,7 +366,8 @@ do {				\
 			}
 
 			if ((lvl & P(LVL, REM_RAM1)) ||
-			    (lvl & P(LVL, REM_RAM2))) {
+			    (lvl & P(LVL, REM_RAM2)) ||
+			     mrem) {
 				stats->rmt_dram++;
 				if (snoop & P(SNOOP, HIT))
 					stats->ld_shared++;
@@ -371,7 +377,8 @@ do {				\
 		}
 
 		if ((lvl & P(LVL, REM_CCE1)) ||
-		    (lvl & P(LVL, REM_CCE2))) {
+		    (lvl & P(LVL, REM_CCE2)) ||
+		     mrem) {
 			if (snoop & P(SNOOP, HIT))
 				stats->rmt_hit++;
 			else if (snoop & P(SNOOP, HITM))