Re: [PATCH v3 2/2] perf stat: Support regex pattern in --for-each-cgroup

Arnaldo Carvalho de Melo
2020-10-27T15:07:51Z

Em Tue, Oct 27, 2020 at 02:44:21PM +0100, Jiri Olsa escreveu:
> On Tue, Oct 27, 2020 at 04:28:55PM +0900, Namhyung Kim wrote:
> > 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: Namhyung Kim <namhyung@kernel.org>
>
> Acked-by: Jiri Olsa <jolsa@redhat.com>

Thanks, applied both patches.

- Arnaldo

> thanks,
> jirka
>
> > ---
> > tools/perf/Documentation/perf-stat.txt | 5 +-
> > tools/perf/builtin-stat.c | 5 +-
> > tools/perf/util/cgroup.c | 198 ++++++++++++++++++++++---
> > 3 files changed, 182 insertions(+), 26 deletions(-)
> >
> > diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
> > index 9f9f29025e49..2b44c08b3b23 100644
> > --- a/tools/perf/Documentation/perf-stat.txt
> > +++ b/tools/perf/Documentation/perf-stat.txt
> > @@ -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::
> > diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> > index b01af171d94f..6709578128c9 100644
> > --- a/tools/perf/builtin-stat.c
> > +++ b/tools/perf/builtin-stat.c
> > @@ -2235,8 +2235,11 @@ 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);
> > diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
> > index b81324a13a2b..704333748549 100644
> > --- a/tools/perf/util/cgroup.c
> > +++ b/tools/perf/util/cgroup.c
> > @@ -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)
> > - goto out_err;
> > + if (prefix_len < 0)
> > + goto out_err;
> >
> > - cgrp = cgroup__new(name, open_cgroup);
> > - free(name);
> > - if (cgrp == NULL)
> > - goto out_err;
> > - } else {
> > - cgrp = NULL;
> > - }
> > + 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);
> > + if (cgrp == NULL)
> > + goto out_err;
> >
> > 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;
> > }
> > --
> > 2.29.0.rc2.309.g374f81d7ae-goog
> >
>

--

- Arnaldo