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perf stat: Add stalled cycles accounting, prettify the resulting output

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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@chello.nl>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-uapziqny39601apdmmhoz7hk@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar 2011-04-27 04:34:16 +02:00
parent dcd9936a5a
commit 481f988a01
1 changed files with 31 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
tools/perf/builtin-stat.c
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@ -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) {
total = avg_stats(&runtime_nsecs_stats[cpu]);
if (total)
ratio = 1000.0 * 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]);
if (total)
ratio = avg / total * 100.0;
fprintf(stderr, " # (%5.2f%% of all cycles )", ratio);
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 = 1.0 * avg / total;
fprintf(stderr, " # %8.3f GHz ", ratio);
} else if (runtime_nsecs_stats[cpu].n != 0) {
total = avg_stats(&runtime_nsecs_stats[cpu]);
if (total)
ratio = 1000.0 * avg / total;
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));
}