Commit bb1c15b6 authored by Namhyung Kim's avatar Namhyung Kim Committed by Arnaldo Carvalho de Melo
Browse files

perf stat: Support regex pattern in --for-each-cgroup 



To make the command line even more compact with cgroups, support regex
pattern matching in cgroup names.

  $ perf stat -a -e cpu-clock,cycles --for-each-cgroup ^foo sleep 1

          3,000.73 msec cpu-clock                 foo #    2.998 CPUs utilized
    12,530,992,699      cycles                    foo #    7.517 GHz                      (100.00%)
          1,000.61 msec cpu-clock                 foo/bar #    1.000 CPUs utilized
     4,178,529,579      cycles                    foo/bar #    2.506 GHz                      (100.00%)
          1,000.03 msec cpu-clock                 foo/baz #    0.999 CPUs utilized
     4,176,104,315      cycles                    foo/baz #    2.505 GHz                      (100.00%)

       1.000892614 seconds time elapsed

Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201027072855.655449-2-namhyung@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 9b0a7836

tools/perf/Documentation/perf-stat.txt

+3 −2
Original line number Diff line number Diff line
@@ -168,8 +168,9 @@ command line can be used: 'perf stat -e cycles -G cgroup_name -a -e cycles'. 


--for-each-cgroup name::

Expand event list for each cgroup in "name" (allow multiple cgroups separated

by comma).  This has same effect that repeating -e option and -G option for

each event x name.  This option cannot be used with -G/--cgroup option.

by comma).  It also support regex patterns to match multiple groups.  This has same

effect that repeating -e option and -G option for each event x name.  This option

cannot be used with -G/--cgroup option.



-o file::

--output file::

tools/perf/builtin-stat.c

+4 −1
Original line number Diff line number Diff line
@@ -2235,9 +2235,12 @@ int cmd_stat(int argc, const char **argv) 
		}



		if (evlist__expand_cgroup(evsel_list, stat_config.cgroup_list,

					  &stat_config.metric_events, true) < 0)

					  &stat_config.metric_events, true) < 0) {

			parse_options_usage(stat_usage, stat_options,

					    "for-each-cgroup", 0);

			goto out;

		}

	}



	target__validate(&target);

tools/perf/util/cgroup.c

+175 −23
Original line number Diff line number Diff line
@@ -13,9 +13,19 @@ 
#include <stdlib.h>

#include <string.h>

#include <api/fs/fs.h>

#include <ftw.h>

#include <regex.h>



int nr_cgroups;



/* used to match cgroup name with patterns */

struct cgroup_name {

	struct list_head list;

	bool used;

	char name[];

};

static LIST_HEAD(cgroup_list);



static int open_cgroup(const char *name)

{

	char path[PATH_MAX + 1];
@@ -149,6 +159,137 @@ void evlist__set_default_cgroup(struct evlist *evlist, struct cgroup *cgroup) 
		evsel__set_default_cgroup(evsel, cgroup);

}



/* helper function for ftw() in match_cgroups and list_cgroups */

static int add_cgroup_name(const char *fpath, const struct stat *sb __maybe_unused,

			   int typeflag)

{

	struct cgroup_name *cn;



	if (typeflag != FTW_D)

		return 0;



	cn = malloc(sizeof(*cn) + strlen(fpath) + 1);

	if (cn == NULL)

		return -1;



	cn->used = false;

	strcpy(cn->name, fpath);



	list_add_tail(&cn->list, &cgroup_list);

	return 0;

}



static void release_cgroup_list(void)

{

	struct cgroup_name *cn;



	while (!list_empty(&cgroup_list)) {

		cn = list_first_entry(&cgroup_list, struct cgroup_name, list);

		list_del(&cn->list);

		free(cn);

	}

}



/* collect given cgroups only */

static int list_cgroups(const char *str)

{

	const char *p, *e, *eos = str + strlen(str);

	struct cgroup_name *cn;

	char *s;



	/* use given name as is - for testing purpose */

	for (;;) {

		p = strchr(str, ',');

		e = p ? p : eos;



		if (e - str) {

			int ret;



			s = strndup(str, e - str);

			if (!s)

				return -1;

			/* pretend if it's added by ftw() */

			ret = add_cgroup_name(s, NULL, FTW_D);

			free(s);

			if (ret)

				return -1;

		} else {

			if (add_cgroup_name("", NULL, FTW_D) < 0)

				return -1;

		}



		if (!p)

			break;

		str = p+1;

	}



	/* these groups will be used */

	list_for_each_entry(cn, &cgroup_list, list)

		cn->used = true;



	return 0;

}



/* collect all cgroups first and then match with the pattern */

static int match_cgroups(const char *str)

{

	char mnt[PATH_MAX];

	const char *p, *e, *eos = str + strlen(str);

	struct cgroup_name *cn;

	regex_t reg;

	int prefix_len;

	char *s;



	if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))

		return -1;



	/* cgroup_name will have a full path, skip the root directory */

	prefix_len = strlen(mnt);



	/* collect all cgroups in the cgroup_list */

	if (ftw(mnt, add_cgroup_name, 20) < 0)

		return -1;



	for (;;) {

		p = strchr(str, ',');

		e = p ? p : eos;



		/* allow empty cgroups, i.e., skip */

		if (e - str) {

			/* termination added */

			s = strndup(str, e - str);

			if (!s)

				return -1;

			if (regcomp(&reg, s, REG_NOSUB)) {

				free(s);

				return -1;

			}



			/* check cgroup name with the pattern */

			list_for_each_entry(cn, &cgroup_list, list) {

				char *name = cn->name + prefix_len;



				if (name[0] == '/' && name[1])

					name++;

				if (!regexec(&reg, name, 0, NULL, 0))

					cn->used = true;

			}

			regfree(&reg);

			free(s);

		} else {

			/* first entry to root cgroup */

			cn = list_first_entry(&cgroup_list, struct cgroup_name,

					      list);

			cn->used = true;

		}



		if (!p)

			break;

		str = p+1;

	}

	return prefix_len;

}



int parse_cgroups(const struct option *opt, const char *str,

		  int unset __maybe_unused)

{
@@ -201,6 +342,11 @@ int parse_cgroups(const struct option *opt, const char *str, 
	return 0;

}



static bool has_pattern_string(const char *str)

{

	return !!strpbrk(str, "{}[]()|*+?^$");

}



int evlist__expand_cgroup(struct evlist *evlist, const char *str,

			  struct rblist *metric_events, bool open_cgroup)

{
@@ -208,8 +354,9 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str, 
	struct evsel *pos, *evsel, *leader;

	struct rblist orig_metric_events;

	struct cgroup *cgrp = NULL;

	const char *p, *e, *eos = str + strlen(str);

	struct cgroup_name *cn;

	int ret = -1;

	int prefix_len;



	if (evlist->core.nr_entries == 0) {

		fprintf(stderr, "must define events before cgroups\n");
@@ -234,24 +381,27 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str, 
		rblist__init(&orig_metric_events);

	}



	for (;;) {

		p = strchr(str, ',');

		e = p ? p : eos;

	if (has_pattern_string(str))

		prefix_len = match_cgroups(str);

	else

		prefix_len = list_cgroups(str);



		/* allow empty cgroups, i.e., skip */

		if (e - str) {

			/* termination added */

			char *name = strndup(str, e - str);

			if (!name)

	if (prefix_len < 0)

		goto out_err;



	list_for_each_entry(cn, &cgroup_list, list) {

		char *name;



		if (!cn->used)

			continue;



		/* cgroup_name might have a full path, skip the prefix */

		name = cn->name + prefix_len;

		if (name[0] == '/' && name[1])

			name++;

		cgrp = cgroup__new(name, open_cgroup);

			free(name);

		if (cgrp == NULL)

			goto out_err;

		} else {

			cgrp = NULL;

		}



		leader = NULL;

		evlist__for_each_entry(orig_list, pos) {
@@ -277,23 +427,25 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str, 
			if (metricgroup__copy_metric_events(tmp_list, cgrp,

							    metric_events,

							    &orig_metric_events) < 0)

				break;

				goto out_err;

		}



		perf_evlist__splice_list_tail(evlist, &tmp_list->core.entries);

		tmp_list->core.nr_entries = 0;



		if (!p) {

			ret = 0;

			break;

	}

		str = p+1;



	if (list_empty(&evlist->core.entries)) {

		fprintf(stderr, "no cgroup matched: %s\n", str);

		goto out_err;

	}



	ret = 0;



out_err:

	evlist__delete(orig_list);

	evlist__delete(tmp_list);

	rblist__exit(&orig_metric_events);

	release_cgroup_list();



	return ret;

}