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Commit 12c08a9f authored by Stephane Eranian's avatar Stephane Eranian Committed by Arnaldo Carvalho de Melo
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perf stat: Add per-core aggregation 



This patch adds the --per-core option to perf stat.

This option is used to aggregate system-wide counts
on a per physical core basis. On processors with
hyperthreading, this means counts of all HT threads
running on a physical core are aggregated.

This mode is useful to find imblance between physical
cores running an uniform workload. Cores are identified
by socket: S0-C1, means physical core 1 on socket 0. Note
that cores are identified using their physical core id,
thus their numbering may not be continuous.

Per core aggregation can be combined with interval printing:

 # perf stat -a --per-core -I 1000 -e cycles sleep 1000
 #           time core         cpus             counts events
      1.000090030 S0-C0           1          4,765,747 cycles
      1.000090030 S0-C1           1          5,580,647 cycles
      1.000090030 S0-C2           1            221,181 cycles
      1.000090030 S0-C3           1            266,092 cycles

Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1360846649-6411-4-git-send-email-eranian@google.com


[ committer note: Remove parts already applied on 86ee6e18 to keep bisectability ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent d4304958

tools/perf/Documentation/perf-stat.txt

+6 −0
Original line number Diff line number Diff line
@@ -126,6 +126,12 @@ use --per-socket in addition to -a. (system-wide). The output includes the 
socket number and the number of online processors on that socket. This is

useful to gauge the amount of aggregation.



--per-core::

Aggregate counts per physical processor for system-wide mode measurements.  This

is a useful mode to detect imbalance between physical cores.  To enable this mode,

use --per-core in addition to -a. (system-wide).  The output includes the

core number and the number of online logical processors on that physical processor.



EXAMPLES

--------

tools/perf/builtin-stat.c

+28 −3
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ enum aggr_mode { 
	AGGR_NONE,

	AGGR_GLOBAL,

	AGGR_SOCKET,

	AGGR_CORE,

};



static int			run_count			=  1;
@@ -384,6 +385,9 @@ static void print_interval(void) 
		case AGGR_SOCKET:

			fprintf(output, "#           time socket cpus             counts events\n");

			break;

		case AGGR_CORE:

			fprintf(output, "#           time core         cpus             counts events\n");

			break;

		case AGGR_NONE:

			fprintf(output, "#           time CPU                 counts events\n");

			break;
@@ -397,6 +401,7 @@ static void print_interval(void) 
		num_print_interval = 0;



	switch (aggr_mode) {

	case AGGR_CORE:

	case AGGR_SOCKET:

		print_aggr(prefix);

		break;
@@ -566,13 +571,23 @@ static void print_noise(struct perf_evsel *evsel, double avg) 
	print_noise_pct(stddev_stats(&ps->res_stats[0]), avg);

}



static void aggr_printout(struct perf_evsel *evsel, int cpu, int nr)

static void aggr_printout(struct perf_evsel *evsel, int id, int nr)

{

	switch (aggr_mode) {

	case AGGR_CORE:

		fprintf(output, "S%d-C%*d%s%*d%s",

			cpu_map__id_to_socket(id),

			csv_output ? 0 : -8,

			cpu_map__id_to_cpu(id),

			csv_sep,

			csv_output ? 0 : 4,

			nr,

			csv_sep);

		break;

	case AGGR_SOCKET:

		fprintf(output, "S%*d%s%*d%s",

			csv_output ? 0 : -5,

			cpu,

			id,

			csv_sep,

			csv_output ? 0 : 4,

			nr,
@@ -581,7 +596,7 @@ static void aggr_printout(struct perf_evsel *evsel, int cpu, int nr) 
	case AGGR_NONE:

		fprintf(output, "CPU%*d%s",

			csv_output ? 0 : -4,

			perf_evsel__cpus(evsel)->map[cpu], csv_sep);

			perf_evsel__cpus(evsel)->map[id], csv_sep);

		break;

	case AGGR_GLOBAL:

	default:
@@ -1095,6 +1110,7 @@ static void print_stat(int argc, const char **argv) 
	}



	switch (aggr_mode) {

	case AGGR_CORE:

	case AGGR_SOCKET:

		print_aggr(NULL);

		break;
@@ -1163,6 +1179,13 @@ static int perf_stat_init_aggr_mode(void) 
		}

		aggr_get_id = cpu_map__get_socket;

		break;

	case AGGR_CORE:

		if (cpu_map__build_core_map(evsel_list->cpus, &aggr_map)) {

			perror("cannot build core map");

			return -1;

		}

		aggr_get_id = cpu_map__get_core;

		break;

	case AGGR_NONE:

	case AGGR_GLOBAL:

	default:
@@ -1372,6 +1395,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused) 
		    "print counts at regular interval in ms (>= 100)"),

	OPT_SET_UINT(0, "per-socket", &aggr_mode,

		     "aggregate counts per processor socket", AGGR_SOCKET),

	OPT_SET_UINT(0, "per-core", &aggr_mode,

		     "aggregate counts per physical processor core", AGGR_CORE),

	OPT_END()

	};

	const char * const stat_usage[] = {

tools/perf/util/cpumap.c

+46 −0
Original line number Diff line number Diff line
@@ -267,7 +267,53 @@ static int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res, 
	return 0;

}



int cpu_map__get_core(struct cpu_map *map, int idx)

{

	FILE *fp;

	const char *mnt;

	char path[PATH_MAX];

	int cpu, ret, s;



	if (idx > map->nr)

		return -1;



	cpu = map->map[idx];



	mnt = sysfs_find_mountpoint();

	if (!mnt)

		return -1;



	snprintf(path, PATH_MAX,

		"%s/devices/system/cpu/cpu%d/topology/core_id",

		mnt, cpu);



	fp = fopen(path, "r");

	if (!fp)

		return -1;

	ret = fscanf(fp, "%d", &cpu);

	fclose(fp);

	if (ret != 1)

		return -1;



	s = cpu_map__get_socket(map, idx);

	if (s == -1)

		return -1;



	/*

	 * encode socket in upper 16 bits

	 * core_id is relative to socket, and

	 * we need a global id. So we combine

	 * socket+ core id

	 */

	return (s << 16) | (cpu & 0xffff);

}



int cpu_map__build_socket_map(struct cpu_map *cpus, struct cpu_map **sockp)

{

	return cpu_map__build_map(cpus, sockp, cpu_map__get_socket);

}



int cpu_map__build_core_map(struct cpu_map *cpus, struct cpu_map **corep)

{

	return cpu_map__build_map(cpus, corep, cpu_map__get_core);

}

tools/perf/util/cpumap.h

+12 −0
Original line number Diff line number Diff line
@@ -15,7 +15,9 @@ void cpu_map__delete(struct cpu_map *map); 
struct cpu_map *cpu_map__read(FILE *file);

size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp);

int cpu_map__get_socket(struct cpu_map *map, int idx);

int cpu_map__get_core(struct cpu_map *map, int idx);

int cpu_map__build_socket_map(struct cpu_map *cpus, struct cpu_map **sockp);

int cpu_map__build_core_map(struct cpu_map *cpus, struct cpu_map **corep);



static inline int cpu_map__socket(struct cpu_map *sock, int s)

{
@@ -24,6 +26,16 @@ static inline int cpu_map__socket(struct cpu_map *sock, int s) 
	return sock->map[s];

}



static inline int cpu_map__id_to_socket(int id)

{

	return id >> 16;

}



static inline int cpu_map__id_to_cpu(int id)

{

	return id & 0xffff;

}



static inline int cpu_map__nr(const struct cpu_map *map)

{

	return map ? map->nr : 1;