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authorKan Liang <Kan.liang@intel.com>2017-05-26 12:05:38 -0700
committerArnaldo Carvalho de Melo <acme@redhat.com>2017-06-21 11:35:35 -0300
commitdaefd0bc0bd28cea2e6b2f3e1a9da005cd4f58fc (patch)
tree81eaf64f1c5ad6f199d88322616c4c6eca157e0e /tools/perf/util/stat.c
parent3b00ea938653d136c8e4bcbe9722d954e128ce2e (diff)
downloadlinux-daefd0bc0bd28cea2e6b2f3e1a9da005cd4f58fc.tar.bz2
perf stat: Add support to measure SMI cost
Implementing a new --smi-cost mode in perf stat to measure SMI cost. During the measurement, the /sys/device/cpu/freeze_on_smi will be set. The measurement can be done with one counter (unhalted core cycles), and two free running MSR counters (IA32_APERF and SMI_COUNT). In practice, the percentages of SMI core cycles should be more useful than absolute value. So the output will be the percentage of SMI core cycles and SMI#. metric_only will be set by default. SMI cycles% = (aperf - unhalted core cycles) / aperf Here is an example output. Performance counter stats for 'sudo echo ': SMI cycles% SMI# 0.1% 1 0.010858678 seconds time elapsed Users who wants to get the actual value can apply additional --no-metric-only. Signed-off-by: Kan Liang <Kan.liang@intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robert Elliott <elliott@hpe.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1495825538-5230-3-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/stat.c')
-rw-r--r--tools/perf/util/stat.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index c58174443dc1..53b9a994a3dc 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -86,6 +86,8 @@ static const char *id_str[PERF_STAT_EVSEL_ID__MAX] = {
ID(TOPDOWN_SLOTS_RETIRED, topdown-slots-retired),
ID(TOPDOWN_FETCH_BUBBLES, topdown-fetch-bubbles),
ID(TOPDOWN_RECOVERY_BUBBLES, topdown-recovery-bubbles),
+ ID(SMI_NUM, msr/smi/),
+ ID(APERF, msr/aperf/),
};
#undef ID