Em Tue, Jan 03, 2023 at 10:44:02PM -0800, Namhyung Kim escreveu:
> The --for-each-cgroup can have the same cgroup multiple times, but it makes
> bpf counters confused (since they have the same cgroup id), and the last
> cgroup events are counted only. Let's check the cgroup name before adding
> a new entry.
>
> Before:
> $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1
>
> Performance counter stats for 'system wide':
>
> <not counted> msec cpu-clock /
> <not counted> context-switches /
> <not counted> cpu-migrations /
> <not counted> page-faults /
> <not counted> cycles /
> <not counted> instructions /
> <not counted> branches /
> <not counted> branch-misses /
> 8,016.04 msec cpu-clock / # 7.998 CPUs utilized
> 6,152 context-switches / # 767.461 /sec
> 250 cpu-migrations / # 31.187 /sec
> 442 page-faults / # 55.139 /sec
> 613,111,487 cycles / # 0.076 GHz
> 280,599,604 instructions / # 0.46 insn per cycle
> 57,692,724 branches / # 7.197 M/sec
> 3,385,168 branch-misses / # 5.87% of all branches
>
> 1.002220125 seconds time elapsed
>
> After:
> $ sudo ./perf stat -a --bpf-counters --for-each-cgroup /,/ sleep 1
>
> Performance counter stats for 'system wide':
>
> 8,013.38 msec cpu-clock / # 7.998 CPUs utilized
> 6,859 context-switches / # 855.944 /sec
> 334 cpu-migrations / # 41.680 /sec
> 345 page-faults / # 43.053 /sec
> 782,326,119 cycles / # 0.098 GHz
> 471,645,724 instructions / # 0.60 insn per cycle
> 94,963,430 branches / # 11.851 M/sec
> 3,685,511 branch-misses / # 3.88% of all branches
>
> 1.001864539 seconds time elapsed
>
> Fixes: bb1c15b60b981 ("perf stat: Support regex pattern in --for-each-cgroup")
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Tested and appied.
- Arnaldo
> ---
> tools/perf/util/cgroup.c | 23 ++++++++++++++++++-----
> 1 file changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
> index e99b41f9be45..cd978c240e0d 100644
> --- a/tools/perf/util/cgroup.c
> +++ b/tools/perf/util/cgroup.c
> @@ -224,6 +224,19 @@ static int add_cgroup_name(const char *fpath, const struct stat *sb __maybe_unus
> return 0;
> }
>
> +static int check_and_add_cgroup_name(const char *fpath)
> +{
> + struct cgroup_name *cn;
> +
> + list_for_each_entry(cn, &cgroup_list, list) {
> + if (!strcmp(cn->name, fpath))
> + return 0;
> + }
> +
> + /* pretend if it's added by ftw() */
> + return add_cgroup_name(fpath, NULL, FTW_D, NULL);
> +}
> +
> static void release_cgroup_list(void)
> {
> struct cgroup_name *cn;
> @@ -242,7 +255,7 @@ static int list_cgroups(const char *str)
> struct cgroup_name *cn;
> char *s;
>
> - /* use given name as is - for testing purpose */
> + /* use given name as is when no regex is given */
> for (;;) {
> p = strchr(str, ',');
> e = p ? p : eos;
> @@ -253,13 +266,13 @@ static int list_cgroups(const char *str)
> s = strndup(str, e - str);
> if (!s)
> return -1;
> - /* pretend if it's added by ftw() */
> - ret = add_cgroup_name(s, NULL, FTW_D, NULL);
> +
> + ret = check_and_add_cgroup_name(s);
> free(s);
> - if (ret)
> + if (ret < 0)
> return -1;
> } else {
> - if (add_cgroup_name("", NULL, FTW_D, NULL) < 0)
> + if (check_and_add_cgroup_name("/") < 0)
> return -1;
> }
>
> --
> 2.39.0.314.g84b9a713c41-goog
--
- Arnaldo
