[tip:perf/stat] perf stat: Add stalled cycles accounting, prettify the resulting output
From: tip-bot for Ingo Molnar
Date: Wed Apr 27 2011 - 12:02:11 EST
Commit-ID: 481f988a016f7a0327a5537bde4794349fc4625c
Gitweb: http://git.kernel.org/tip/481f988a016f7a0327a5537bde4794349fc4625c
Author: Ingo Molnar <mingo@xxxxxxx>
AuthorDate: Wed, 27 Apr 2011 04:34:16 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 26 Apr 2011 20:04:56 +0200
perf stat: Add stalled cycles accounting, prettify the resulting output
Add stalled cycles accounting and use it to print the "cycles stalled per
instruction" value.
Also change the unit of the cycles output from M/sec to GHz - this is more
intuitive.
Prettify the output to:
Performance counter stats for './loop_1b_instructions':
239.775036 task-clock # 0.997 CPUs utilized
761,903,912 cycles # 3.178 GHz
356,620,620 stalled-cycles # 46.81% of all cycles are idle
1,001,578,351 instructions # 1.31 insns per cycle
# 0.36 stalled cycles per insn
14,782 cache-references # 0.062 M/sec
5,694 cache-misses # 38.520 % of all cache refs
0.240493656 seconds time elapsed
Also adjust the --repeat output to make the percentages align vertically:
Performance counter stats for './loop_1b_instructions' (10 runs):
236.096793 task-clock # 0.997 CPUs utilized ( +- 0.011% )
756,553,086 cycles # 3.204 GHz ( +- 0.002% )
354,942,692 stalled-cycles # 46.92% of all cycles are idle ( +- 0.008% )
1,001,389,700 instructions # 1.32 insns per cycle
# 0.35 stalled cycles per insn ( +- 0.000% )
10,166 cache-references # 0.043 M/sec ( +- 0.742% )
468 cache-misses # 4.608 % of all cache refs ( +- 13.385% )
0.236874136 seconds time elapsed ( +- 0.01% )
Acked-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Link: http://lkml.kernel.org/n/tip-uapziqny39601apdmmhoz7hk@xxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
tools/perf/builtin-stat.c | 43 ++++++++++++++++++++++++++++++-------------
1 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index e5e82f6..e881c20 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -156,6 +156,7 @@ static double stddev_stats(struct stats *stats)
struct stats runtime_nsecs_stats[MAX_NR_CPUS];
struct stats runtime_cycles_stats[MAX_NR_CPUS];
+struct stats runtime_stalled_cycles_stats[MAX_NR_CPUS];
struct stats runtime_branches_stats[MAX_NR_CPUS];
struct stats runtime_cacherefs_stats[MAX_NR_CPUS];
struct stats walltime_nsecs_stats;
@@ -204,6 +205,8 @@ static void update_shadow_stats(struct perf_evsel *counter, u64 *count)
update_stats(&runtime_nsecs_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
update_stats(&runtime_cycles_stats[0], count[0]);
+ else if (perf_evsel__match(counter, HARDWARE, HW_STALLED_CYCLES))
+ update_stats(&runtime_stalled_cycles_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
update_stats(&runtime_branches_stats[0], count[0]);
else if (perf_evsel__match(counter, HARDWARE, HW_CACHE_REFERENCES))
@@ -412,8 +415,7 @@ static void nsec_printout(int cpu, struct perf_evsel *evsel, double avg)
return;
if (perf_evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK))
- fprintf(stderr, " # %10.3f CPUs",
- avg / avg_stats(&walltime_nsecs_stats));
+ fprintf(stderr, " # %8.3f CPUs utilized ", avg / avg_stats(&walltime_nsecs_stats));
}
static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
@@ -450,7 +452,15 @@ static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
if (total)
ratio = avg / total;
- fprintf(stderr, " # ( %4.2f instructions per cycle )", ratio);
+ fprintf(stderr, " # %4.2f insns per cycle", ratio);
+
+ total = avg_stats(&runtime_stalled_cycles_stats[cpu]);
+
+ if (total && avg) {
+ ratio = total / avg;
+ fprintf(stderr, "\n # %4.2f stalled cycles per insn", ratio);
+ }
+
} else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES) &&
runtime_branches_stats[cpu].n != 0) {
total = avg_stats(&runtime_branches_stats[cpu]);
@@ -458,7 +468,7 @@ static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
if (total)
ratio = avg * 100 / total;
- fprintf(stderr, " # %10.3f %%", ratio);
+ fprintf(stderr, " # %8.3f %% of all branches", ratio);
} else if (perf_evsel__match(evsel, HARDWARE, HW_CACHE_MISSES) &&
runtime_cacherefs_stats[cpu].n != 0) {
@@ -467,22 +477,29 @@ static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)
if (total)
ratio = avg * 100 / total;
- fprintf(stderr, " # %10.3f %%", ratio);
+ fprintf(stderr, " # %8.3f %% of all cache refs ", ratio);
- } else if (runtime_nsecs_stats[cpu].n != 0) {
+ } else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES)) {
+ total = avg_stats(&runtime_cycles_stats[cpu]);
+
+ if (total)
+ ratio = avg / total * 100.0;
+
+ fprintf(stderr, " # %5.2f%% of all cycles are idle ", ratio);
+ } else if (perf_evsel__match(evsel, HARDWARE, HW_CPU_CYCLES)) {
total = avg_stats(&runtime_nsecs_stats[cpu]);
if (total)
- ratio = 1000.0 * avg / total;
+ ratio = 1.0 * avg / total;
- fprintf(stderr, " # %10.3f M/sec", ratio);
- } else if (perf_evsel__match(evsel, HARDWARE, HW_STALLED_CYCLES)) {
- total = avg_stats(&runtime_cycles_stats[cpu]);
+ fprintf(stderr, " # %8.3f GHz ", ratio);
+ } else if (runtime_nsecs_stats[cpu].n != 0) {
+ total = avg_stats(&runtime_nsecs_stats[cpu]);
if (total)
- ratio = avg / total * 100.0;
+ ratio = 1000.0 * avg / total;
- fprintf(stderr, " # (%5.2f%% of all cycles )", ratio);
+ fprintf(stderr, " # %8.3f M/sec ", ratio);
}
}
@@ -619,7 +636,7 @@ static void print_stat(int argc, const char **argv)
fprintf(stderr, " %18.9f seconds time elapsed",
avg_stats(&walltime_nsecs_stats)/1e9);
if (run_count > 1) {
- fprintf(stderr, " ( +- %7.3f%% )",
+ fprintf(stderr, " ( +-%5.2f%% )",
100*stddev_stats(&walltime_nsecs_stats) /
avg_stats(&walltime_nsecs_stats));
}
--
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