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

From: tip-bot for Jiri Olsa
Date: Tue Aug 29 2017 - 17:22:15 EST


Commit-ID: 12c15302dd4b768105d4b7a487ed4858ccab94fc
Gitweb: http://git.kernel.org/tip/12c15302dd4b768105d4b7a487ed4858ccab94fc
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Thu, 24 Aug 2017 10:57:32 +0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
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@xxxxxxxxxxxxxx

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Joe Mario <jmario@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20170824085732.28481-1-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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))