From 481f988a016f7a0327a5537bde4794349fc4625c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 27 Apr 2011 04:34:16 +0200 Subject: [PATCH] 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 Acked-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Link: http://lkml.kernel.org/n/tip-uapziqny39601apdmmhoz7hk@git.kernel.org Signed-off-by: Ingo Molnar --- tools/perf/builtin-stat.c | 43 +++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index e5e82f62c784..e881c2061381 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)); } -- 2.20.1