Re: [PATCH 3/5] perf tools: Copy metric events properly when expand cgroups

Jiri Olsa
2020-09-23T10:23:12Z

On Wed, Sep 23, 2020 at 10:59:43AM +0900, Namhyung Kim wrote:

SNIP

> diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
> index 8b6a4fa49082..dcd18ef268a1 100644
> --- a/tools/perf/util/cgroup.c
> +++ b/tools/perf/util/cgroup.c
> @@ -3,6 +3,9 @@
> #include "evsel.h"
> #include "cgroup.h"
> #include "evlist.h"
> +#include "rblist.h"
> +#include "metricgroup.h"
> +#include "stat.h"
> #include <linux/zalloc.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> @@ -193,10 +196,12 @@ int parse_cgroups(const struct option *opt, const char *str,
> return 0;
> }
>
> -int evlist__expand_cgroup(struct evlist *evlist, const char *str)
> +int evlist__expand_cgroup(struct evlist *evlist, const char *str,
> + struct rblist *metric_events)
> {
> struct evlist *orig_list, *tmp_list;
> struct evsel *pos, *evsel, *leader;
> + struct rblist orig_metric_events;
> struct cgroup *cgrp = NULL;
> const char *p, *e, *eos = str + strlen(str);
> int ret = -1;
> @@ -216,6 +221,8 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
> /* save original events and init evlist */
> perf_evlist__splice_list_tail(orig_list, &evlist->core.entries);
> evlist->core.nr_entries = 0;
> + orig_metric_events = *metric_events;
> + rblist__init(metric_events);
>
> for (;;) {
> p = strchr(str, ',');
> @@ -255,6 +262,11 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
> cgroup__put(cgrp);
> nr_cgroups++;
>
> + perf_stat__collect_metric_expr(tmp_list);

I know you added the option just for perf stat, not record,
but the code looks generic apart from using this function

I wonder if this would cause any issues if it was called in record
context.. maybe we could just skip it in that case, but that's for
future to worry about ;-)

jirka

> + if (metricgroup__copy_metric_events(tmp_list, cgrp, metric_events,
> + &orig_metric_events) < 0)
> + break;
> +
> perf_evlist__splice_list_tail(evlist, &tmp_list->core.entries);
> tmp_list->core.nr_entries = 0;
>
> @@ -268,6 +280,7 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str)
> out_err:
> evlist__delete(orig_list);
> evlist__delete(tmp_list);
> + rblist__exit(&orig_metric_events);
>
> return ret;
> }

SNIP