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: Stephane 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 86ee6e1 to keep bisectability ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 46027e1..2fe87fb 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -126,6 +126,12 @@
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
--------
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 6f6ea931..7e910ba 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -80,6 +80,7 @@
AGGR_NONE,
AGGR_GLOBAL,
AGGR_SOCKET,
+ AGGR_CORE,
};
static int run_count = 1;
@@ -384,6 +385,9 @@
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 @@
num_print_interval = 0;
switch (aggr_mode) {
+ case AGGR_CORE:
case AGGR_SOCKET:
print_aggr(prefix);
break;
@@ -566,13 +571,23 @@
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 @@
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 @@
}
switch (aggr_mode) {
+ case AGGR_CORE:
case AGGR_SOCKET:
print_aggr(NULL);
break;
@@ -1163,6 +1179,13 @@
}
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 @@
"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[] = {
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index 7bb8e87..beb8cf9 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -267,7 +267,53 @@
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);
+}
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index 161b007..9bed02e 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -15,7 +15,9 @@
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 @@
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;