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perf stat: Print cache misses as percentage
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Before:

       113,393,041 cache-references         #     83.636 M/sec
         7,052,454 cache-misses             #      5.202 M/sec

After:

       112,589,441 cache-references         #     87.925 M/sec
         6,556,354 cache-misses             #      5.823 %

misses/hits percentages are more expressive than absolute numbers
or rates.

(Also prettify the CPUs printout line to not have a trailing whitespace.)

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-axm28f43x439bl41zkvfzd63@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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Ingo Molnar committed Apr 26, 2011
1 parent 11ba2b8 commit d58f4c8
Showing 1 changed file with 15 additions and 3 deletions.
18 changes: 15 additions & 3 deletions tools/perf/builtin-stat.c
Original file line number Diff line number Diff line change
Expand Up @@ -157,6 +157,7 @@ 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_branches_stats[MAX_NR_CPUS];
struct stats runtime_cacherefs_stats[MAX_NR_CPUS];
struct stats walltime_nsecs_stats;

static int create_perf_stat_counter(struct perf_evsel *evsel)
Expand Down Expand Up @@ -219,10 +220,12 @@ static int read_counter_aggr(struct perf_evsel *counter)
*/
if (perf_evsel__match(counter, SOFTWARE, SW_TASK_CLOCK))
update_stats(&runtime_nsecs_stats[0], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
else if (perf_evsel__match(counter, HARDWARE, HW_CPU_CYCLES))
update_stats(&runtime_cycles_stats[0], count[0]);
if (perf_evsel__match(counter, HARDWARE, HW_BRANCH_INSTRUCTIONS))
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))
update_stats(&runtime_cacherefs_stats[0], count[0]);

return 0;
}
Expand Down Expand Up @@ -404,7 +407,7 @@ 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 ",
fprintf(stderr, " # %10.3f CPUs",
avg / avg_stats(&walltime_nsecs_stats));
}

Expand Down Expand Up @@ -452,6 +455,15 @@ static void abs_printout(int cpu, struct perf_evsel *evsel, double avg)

fprintf(stderr, " # %10.3f %%", ratio);

} else if (perf_evsel__match(evsel, HARDWARE, HW_CACHE_MISSES) &&
runtime_cacherefs_stats[cpu].n != 0) {
total = avg_stats(&runtime_cacherefs_stats[cpu]);

if (total)
ratio = avg * 100 / total;

fprintf(stderr, " # %10.3f %%", ratio);

} else if (runtime_nsecs_stats[cpu].n != 0) {
total = avg_stats(&runtime_nsecs_stats[cpu]);

Expand Down

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