tools/perf/stat: Add event unit and scale support
This patch adds perf stat support for handling event units and
scales as exported by the kernel.
The kernel can export PMU events actual unit and scaling factor
via sysfs:
$ ls -1 /sys/devices/power/events/energy-*
/sys/devices/power/events/energy-cores
/sys/devices/power/events/energy-cores.scale
/sys/devices/power/events/energy-cores.unit
/sys/devices/power/events/energy-pkg
/sys/devices/power/events/energy-pkg.scale
/sys/devices/power/events/energy-pkg.unit
$ cat /sys/devices/power/events/energy-cores.scale
2.3283064365386962890625e-10
$ cat cat /sys/devices/power/events/energy-cores.unit
Joules
This patch modifies the pmu event alias code to check
for the presence of the .unit and .scale files to load
the corresponding values. They are then used by perf stat
transparently:
# perf stat -a -e power/energy-pkg/,power/energy-cores/,cycles -I 1000 sleep 1000
# time counts unit events
1.000214717 3.07 Joules power/energy-pkg/ [100.00%]
1.000214717 0.53 Joules power/energy-cores/
1.000214717 12965028 cycles [100.00%]
2.000749289 3.01 Joules power/energy-pkg/
2.000749289 0.52 Joules power/energy-cores/
2.000749289 15817043 cycles
When the event does not have an explicit unit exported by
the kernel, nothing is printed. In csv output mode, there
will be an empty field.
Special thanks to Jiri for providing the supporting code
in the parser to trigger reading of the scale and unit files.
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: zheng.z.yan@intel.com
Cc: bp@alien8.de
Cc: maria.n.dimakopoulou@gmail.com
Cc: acme@redhat.com
Link: http://lkml.kernel.org/r/1384275531-10892-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index c232d8d..56fc10a 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -1,19 +1,23 @@
#include <linux/list.h>
#include <sys/types.h>
-#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <dirent.h>
#include "fs.h"
+#include <locale.h>
#include "util.h"
#include "pmu.h"
#include "parse-events.h"
#include "cpumap.h"
+#define UNIT_MAX_LEN 31 /* max length for event unit name */
+
struct perf_pmu_alias {
char *name;
struct list_head terms;
struct list_head list;
+ char unit[UNIT_MAX_LEN+1];
+ double scale;
};
struct perf_pmu_format {
@@ -94,7 +98,80 @@
return 0;
}
-static int perf_pmu__new_alias(struct list_head *list, char *name, FILE *file)
+static int perf_pmu__parse_scale(struct perf_pmu_alias *alias, char *dir, char *name)
+{
+ struct stat st;
+ ssize_t sret;
+ char scale[128];
+ int fd, ret = -1;
+ char path[PATH_MAX];
+ char *lc;
+
+ snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
+
+ fd = open(path, O_RDONLY);
+ if (fd == -1)
+ return -1;
+
+ if (fstat(fd, &st) < 0)
+ goto error;
+
+ sret = read(fd, scale, sizeof(scale)-1);
+ if (sret < 0)
+ goto error;
+
+ scale[sret] = '\0';
+ /*
+ * save current locale
+ */
+ lc = setlocale(LC_NUMERIC, NULL);
+
+ /*
+ * force to C locale to ensure kernel
+ * scale string is converted correctly.
+ * kernel uses default C locale.
+ */
+ setlocale(LC_NUMERIC, "C");
+
+ alias->scale = strtod(scale, NULL);
+
+ /* restore locale */
+ setlocale(LC_NUMERIC, lc);
+
+ ret = 0;
+error:
+ close(fd);
+ return ret;
+}
+
+static int perf_pmu__parse_unit(struct perf_pmu_alias *alias, char *dir, char *name)
+{
+ char path[PATH_MAX];
+ ssize_t sret;
+ int fd;
+
+ snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
+
+ fd = open(path, O_RDONLY);
+ if (fd == -1)
+ return -1;
+
+ sret = read(fd, alias->unit, UNIT_MAX_LEN);
+ if (sret < 0)
+ goto error;
+
+ close(fd);
+
+ alias->unit[sret] = '\0';
+
+ return 0;
+error:
+ close(fd);
+ alias->unit[0] = '\0';
+ return -1;
+}
+
+static int perf_pmu__new_alias(struct list_head *list, char *dir, char *name, FILE *file)
{
struct perf_pmu_alias *alias;
char buf[256];
@@ -110,6 +187,9 @@
return -ENOMEM;
INIT_LIST_HEAD(&alias->terms);
+ alias->scale = 1.0;
+ alias->unit[0] = '\0';
+
ret = parse_events_terms(&alias->terms, buf);
if (ret) {
free(alias);
@@ -117,7 +197,14 @@
}
alias->name = strdup(name);
+ /*
+ * load unit name and scale if available
+ */
+ perf_pmu__parse_unit(alias, dir, name);
+ perf_pmu__parse_scale(alias, dir, name);
+
list_add_tail(&alias->list, list);
+
return 0;
}
@@ -129,6 +216,7 @@
{
struct dirent *evt_ent;
DIR *event_dir;
+ size_t len;
int ret = 0;
event_dir = opendir(dir);
@@ -143,13 +231,24 @@
if (!strcmp(name, ".") || !strcmp(name, ".."))
continue;
+ /*
+ * skip .unit and .scale info files
+ * parsed in perf_pmu__new_alias()
+ */
+ len = strlen(name);
+ if (len > 5 && !strcmp(name + len - 5, ".unit"))
+ continue;
+ if (len > 6 && !strcmp(name + len - 6, ".scale"))
+ continue;
+
snprintf(path, PATH_MAX, "%s/%s", dir, name);
ret = -EINVAL;
file = fopen(path, "r");
if (!file)
break;
- ret = perf_pmu__new_alias(head, name, file);
+
+ ret = perf_pmu__new_alias(head, dir, name, file);
fclose(file);
}
@@ -508,16 +607,42 @@
return NULL;
}
+
+static int check_unit_scale(struct perf_pmu_alias *alias,
+ char **unit, double *scale)
+{
+ /*
+ * Only one term in event definition can
+ * define unit and scale, fail if there's
+ * more than one.
+ */
+ if ((*unit && alias->unit) ||
+ (*scale && alias->scale))
+ return -EINVAL;
+
+ if (alias->unit)
+ *unit = alias->unit;
+
+ if (alias->scale)
+ *scale = alias->scale;
+
+ return 0;
+}
+
/*
* Find alias in the terms list and replace it with the terms
* defined for the alias
*/
-int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms)
+int perf_pmu__check_alias(struct perf_pmu *pmu, struct list_head *head_terms,
+ char **unit, double *scale)
{
struct parse_events_term *term, *h;
struct perf_pmu_alias *alias;
int ret;
+ *unit = NULL;
+ *scale = 0;
+
list_for_each_entry_safe(term, h, head_terms, list) {
alias = pmu_find_alias(pmu, term);
if (!alias)
@@ -525,6 +650,11 @@
ret = pmu_alias_terms(alias, &term->list);
if (ret)
return ret;
+
+ ret = check_unit_scale(alias, unit, scale);
+ if (ret)
+ return ret;
+
list_del(&term->list);
free(term);
}