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: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri 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: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 9f9f290..2b44c08 100644 (file)
--- 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 b01af17..6709578 100644 (file)
--- 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 b81324a..7043337 100644 (file)
--- 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;
 }