Commit f5b4a9c3 authored by Stephane Eranian's avatar Stephane Eranian Committed by Arnaldo Carvalho de Melo
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perf stat: Add no-aggregation mode to -a 



This patch adds a new -A option to perf stat. If specified then perf stat does
not aggregate counts across all monitored CPUs in system-wide mode, i.e., when
using -a. This option is not supported in per-thread mode.

Being able to get a per-cpu breakdown is useful to detect imbalances between
CPUs when running a uniform workload than spans all monitored CPUs.

The second version corrects the missing cpumap[] support, so that it works when
the -C option is used.

The third version fixes a missing cpumap[] in print_counter() and removes a
stray patch in builtin-trace.c.

Examples on a 4-way system:

# perf stat -a   -e cycles,instructions -- sleep 1
 Performance counter stats for 'sleep 1':
         9592808135  cycles
         3490380006  instructions             #      0.364 IPC
        1.001584632  seconds time elapsed

# perf stat -a -A -e cycles,instructions -- sleep 1
 Performance counter stats for 'sleep 1':
CPU0            2398163767  cycles
CPU1            2398180817  cycles
CPU2            2398217115  cycles
CPU3            2398247483  cycles
CPU0             872282046  instructions             #      0.364 IPC
CPU1             873481776  instructions             #      0.364 IPC
CPU2             872638127  instructions             #      0.364 IPC
CPU3             872437789  instructions             #      0.364 IPC
        1.001556052  seconds time elapsed

Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4ce257b5.1e07e30a.7b6b.3aa9@mx.google.com>
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent ae51ce90

tools/perf/Documentation/perf-stat.txt

+5 −0
Original line number Diff line number Diff line
@@ -53,6 +53,11 @@ comma-sperated list with no space: 0,1. Ranges of CPUs are specified with -: 0-2 
In per-thread mode, this option is ignored. The -a option is still necessary

to activate system-wide monitoring. Default is to count on all CPUs.



-A::

--no-aggr::

Do not aggregate counts across all monitored CPUs in system-wide mode (-a).

This option is only valid in system-wide mode.



EXAMPLES

--------

tools/perf/builtin-stat.c

+144 −25
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ static int run_idx = 0; 
static int			run_count			=  1;

static bool			no_inherit			= false;

static bool			scale				=  true;

static bool			no_aggr				= false;

static pid_t			target_pid			= -1;

static pid_t			target_tid			= -1;

static pid_t			*all_tids			=  NULL;
@@ -89,6 +90,12 @@ static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; 


static int			event_scaled[MAX_COUNTERS];



static struct {

	u64 val;

	u64 ena;

	u64 run;

} cpu_counts[MAX_NR_CPUS][MAX_COUNTERS];



static volatile int done = 0;



struct stats
@@ -136,10 +143,10 @@ static double stddev_stats(struct stats *stats) 
}



struct stats			event_res_stats[MAX_COUNTERS][3];

struct stats			runtime_nsecs_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			walltime_nsecs_stats;

struct stats			runtime_cycles_stats;

struct stats			runtime_branches_stats;



#define MATCH_EVENT(t, c, counter)			\

	(attrs[counter].type == PERF_TYPE_##t &&	\
@@ -205,8 +212,9 @@ static inline int nsec_counter(int counter) 


/*

 * Read out the results of a single counter:

 * aggregate counts across CPUs in system-wide mode

 */

static void read_counter(int counter)

static void read_counter_aggr(int counter)

{

	u64 count[3], single_count[3];

	int cpu;
@@ -264,11 +272,58 @@ static void read_counter(int counter) 
	 * Save the full runtime - to allow normalization during printout:

	 */

	if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))

		update_stats(&runtime_nsecs_stats, count[0]);

		update_stats(&runtime_nsecs_stats[0], count[0]);

	if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))

		update_stats(&runtime_cycles_stats, count[0]);

		update_stats(&runtime_cycles_stats[0], count[0]);

	if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))

		update_stats(&runtime_branches_stats, count[0]);

		update_stats(&runtime_branches_stats[0], count[0]);

}



/*

 * Read out the results of a single counter:

 * do not aggregate counts across CPUs in system-wide mode

 */

static void read_counter(int counter)

{

	u64 count[3];

	int cpu;

	size_t res, nv;



	count[0] = count[1] = count[2] = 0;



	nv = scale ? 3 : 1;



	for (cpu = 0; cpu < nr_cpus; cpu++) {



		if (fd[cpu][counter][0] < 0)

			continue;



		res = read(fd[cpu][counter][0], count, nv * sizeof(u64));



		assert(res == nv * sizeof(u64));



		close(fd[cpu][counter][0]);

		fd[cpu][counter][0] = -1;



		if (scale) {

			if (count[2] == 0) {

				count[0] = 0;

			} else if (count[2] < count[1]) {

				count[0] = (unsigned long long)

				((double)count[0] * count[1] / count[2] + 0.5);

			}

		}

		cpu_counts[cpu][counter].val = count[0]; /* scaled count */

		cpu_counts[cpu][counter].ena = count[1];

		cpu_counts[cpu][counter].run = count[2];



		if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter))

			update_stats(&runtime_nsecs_stats[cpu], count[0]);

		if (MATCH_EVENT(HARDWARE, HW_CPU_CYCLES, counter))

			update_stats(&runtime_cycles_stats[cpu], count[0]);

		if (MATCH_EVENT(HARDWARE, HW_BRANCH_INSTRUCTIONS, counter))

			update_stats(&runtime_branches_stats[cpu], count[0]);

	}

}



static int run_perf_stat(int argc __used, const char **argv)
@@ -362,9 +417,13 @@ static int run_perf_stat(int argc __used, const char **argv) 


	update_stats(&walltime_nsecs_stats, t1 - t0);



	if (no_aggr) {

		for (counter = 0; counter < nr_counters; counter++)

			read_counter(counter);



	} else {

		for (counter = 0; counter < nr_counters; counter++)

			read_counter_aggr(counter);

	}

	return WEXITSTATUS(status);

}
@@ -377,10 +436,14 @@ static void print_noise(int counter, double avg) 
			100 * stddev_stats(&event_res_stats[counter][0]) / avg);

}



static void nsec_printout(int counter, double avg)

static void nsec_printout(int cpu, int counter, double avg)

{

	double msecs = avg / 1e6;



	if (no_aggr)

		fprintf(stderr, "CPU%-4d %18.6f  %-24s",

			cpumap[cpu], msecs, event_name(counter));

	else

		fprintf(stderr, " %18.6f  %-24s", msecs, event_name(counter));



	if (MATCH_EVENT(SOFTWARE, SW_TASK_CLOCK, counter)) {
@@ -389,33 +452,41 @@ static void nsec_printout(int counter, double avg) 
	}

}



static void abs_printout(int counter, double avg)

static void abs_printout(int cpu, int counter, double avg)

{

	double total, ratio = 0.0;

	char cpustr[16] = { '\0', };



	if (no_aggr)

		sprintf(cpustr, "CPU%-4d", cpumap[cpu]);

	else

		cpu = 0;



	if (big_num)

		fprintf(stderr, " %'18.0f  %-24s", avg, event_name(counter));

		fprintf(stderr, "%s %'18.0f  %-24s",

			cpustr, avg, event_name(counter));

	else

		fprintf(stderr, " %18.0f  %-24s", avg, event_name(counter));

		fprintf(stderr, "%s %18.0f  %-24s",

			cpustr, avg, event_name(counter));



	if (MATCH_EVENT(HARDWARE, HW_INSTRUCTIONS, counter)) {

		total = avg_stats(&runtime_cycles_stats);

		total = avg_stats(&runtime_cycles_stats[cpu]);



		if (total)

			ratio = avg / total;



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

	} else if (MATCH_EVENT(HARDWARE, HW_BRANCH_MISSES, counter) &&

			runtime_branches_stats.n != 0) {

		total = avg_stats(&runtime_branches_stats);

			runtime_branches_stats[cpu].n != 0) {

		total = avg_stats(&runtime_branches_stats[cpu]);



		if (total)

			ratio = avg * 100 / total;



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



	} else if (runtime_nsecs_stats.n != 0) {

		total = avg_stats(&runtime_nsecs_stats);

	} else if (runtime_nsecs_stats[cpu].n != 0) {

		total = avg_stats(&runtime_nsecs_stats[cpu]);



		if (total)

			ratio = 1000.0 * avg / total;
@@ -426,8 +497,9 @@ static void abs_printout(int counter, double avg) 


/*

 * Print out the results of a single counter:

 * aggregated counts in system-wide mode

 */

static void print_counter(int counter)

static void print_counter_aggr(int counter)

{

	double avg = avg_stats(&event_res_stats[counter][0]);

	int scaled = event_scaled[counter];
@@ -439,9 +511,9 @@ static void print_counter(int counter) 
	}



	if (nsec_counter(counter))

		nsec_printout(counter, avg);

		nsec_printout(-1, counter, avg);

	else

		abs_printout(counter, avg);

		abs_printout(-1, counter, avg);



	print_noise(counter, avg);
@@ -458,6 +530,42 @@ static void print_counter(int counter) 
	fprintf(stderr, "\n");

}



/*

 * Print out the results of a single counter:

 * does not use aggregated count in system-wide

 */

static void print_counter(int counter)

{

	u64 ena, run, val;

	int cpu;



	for (cpu = 0; cpu < nr_cpus; cpu++) {

		val = cpu_counts[cpu][counter].val;

		ena = cpu_counts[cpu][counter].ena;

		run = cpu_counts[cpu][counter].run;

		if (run == 0 || ena == 0) {

			fprintf(stderr, "CPU%-4d %18s  %-24s", cpumap[cpu],

					"<not counted>", event_name(counter));



			fprintf(stderr, "\n");

			continue;

		}



		if (nsec_counter(counter))

			nsec_printout(cpu, counter, val);

		else

			abs_printout(cpu, counter, val);



		print_noise(counter, 1.0);



		if (run != ena) {

			fprintf(stderr, "  (scaled from %.2f%%)",

					100.0 * run / ena);

		}

		fprintf(stderr, "\n");

	}

}



static void print_stat(int argc, const char **argv)

{

	int i, counter;
@@ -480,8 +588,13 @@ static void print_stat(int argc, const char **argv) 
		fprintf(stderr, " (%d runs)", run_count);

	fprintf(stderr, ":\n\n");



	if (no_aggr) {

		for (counter = 0; counter < nr_counters; counter++)

			print_counter(counter);

	} else {

		for (counter = 0; counter < nr_counters; counter++)

			print_counter_aggr(counter);

	}



	fprintf(stderr, "\n");

	fprintf(stderr, " %18.9f  seconds time elapsed",
@@ -545,6 +658,8 @@ static const struct option options[] = { 
		    "print large numbers with thousands\' separators"),

	OPT_STRING('C', "cpu", &cpu_list, "cpu",

		    "list of cpus to monitor in system-wide"),

	OPT_BOOLEAN('A', "no-aggr", &no_aggr,

		    "disable CPU count aggregation"),

	OPT_END()

};
@@ -562,6 +677,10 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) 
	if (run_count <= 0)

		usage_with_options(stat_usage, options);



	/* no_aggr is for system-wide only */

	if (no_aggr && !system_wide)

		usage_with_options(stat_usage, options);



	/* Set attrs and nr_counters if no event is selected and !null_run */

	if (!null_run && !nr_counters) {

		memcpy(attrs, default_attrs, sizeof(default_attrs));

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