Re: [PATCH 2/4] perf stat: Add --for-each-cgroup option

From: Namhyung Kim
Date: Mon Sep 21 2020 - 01:46:16 EST


On Fri, Sep 18, 2020 at 10:34 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> On Wed, Sep 16, 2020 at 03:31:27PM +0900, Namhyung Kim wrote:
>
> SNIP
>
> > +int evlist__expand_cgroup(struct evlist *evlist, const char *str)
> > +{
> > + struct evlist *orig_list, *tmp_list;
> > + struct evsel *pos, *evsel, *leader;
> > + struct cgroup *cgrp = NULL;
> > + const char *p, *e, *eos = str + strlen(str);
> > + int ret = -1;
> > +
> > + if (evlist->core.nr_entries == 0) {
> > + fprintf(stderr, "must define events before cgroups\n");
> > + return -EINVAL;
> > + }
> > +
> > + orig_list = evlist__new();
> > + tmp_list = evlist__new();
> > + if (orig_list == NULL || tmp_list == NULL) {
> > + fprintf(stderr, "memory allocation failed\n");
> > + return -ENOMEM;
> > + }
> > +
> > + /* save original events and init evlist */
> > + perf_evlist__splice_list_tail(orig_list, &evlist->core.entries);
> > + evlist->core.nr_entries = 0;
> > +
> > + for (;;) {
> > + p = strchr(str, ',');
> > + e = p ? p : eos;
> > +
> > + /* allow empty cgroups, i.e., skip */
> > + if (e - str) {
> > + /* termination added */
> > + char *name = strndup(str, e - str);
> > + if (!name)
> > + break;
> > +
> > + cgrp = cgroup__new(name);
> > + free(name);
> > + if (cgrp == NULL)
> > + break;
> > + } else {
> > + cgrp = NULL;
> > + }
> > +
> > + leader = NULL;
> > + evlist__for_each_entry(orig_list, pos) {
> > + evsel = evsel__clone(pos);
>
> missing check on evsel == NULL

Will check.

Thanks
Namhyung


> > + cgroup__put(evsel->cgrp);
> > + evsel->cgrp = cgroup__get(cgrp);
> > +
> > + if (evsel__is_group_leader(pos))
> > + leader = evsel;
> > + evsel->leader = leader;
> > +
> > + evlist__add(tmp_list, evsel);
> > + }
> > + /* cgroup__new() has a refcount, release it here */
> > + cgroup__put(cgrp);
> > + nr_cgroups++;
> > +
> > + perf_evlist__splice_list_tail(evlist, &tmp_list->core.entries);
> > + tmp_list->core.nr_entries = 0;
> > +
> > + if (!p) {
> > + ret = 0;
> > + break;
> > + }
> > + str = p+1;
> > + }
> > + evlist__delete(orig_list);
> > + evlist__delete(tmp_list);
> > +
> > + return ret;
> > +}
>
> SNIP
>