On Wed, Sep 23, 2020 at 07:51:33AM +0900, Namhyung Kim wrote:
> On Wed, Sep 23, 2020 at 6:40 AM Jiri Olsa <jo...@redhat.com> wrote:
> >
> > On Mon, Sep 21, 2020 at 06:46:07PM +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)
> > > + goto out_err;
> > > +
> > > + cgrp = cgroup__new(name);
> > > + free(name);
> > > + if (cgrp == NULL)
> > > + goto out_err;
> > > + } else {
> > > + cgrp = NULL;
> > > + }
> > > +
> > > + leader = NULL;
> > > + evlist__for_each_entry(orig_list, pos) {
> > > + evsel = evsel__clone(pos);
> > > + if (evsel == NULL)
> > > + goto out_err;
> > > +
> > > + cgroup__put(evsel->cgrp);
> > > + evsel->cgrp = cgroup__get(cgrp);
> > > +
> > > + if (evsel__is_group_leader(pos))
> > > + leader = evsel;
> > > + evsel->leader = leader;
> >
> > hum, will this work if there's standalone event after group? like:
> >
> > {cycles,instructions},cache-misses
> >
> > cache-misses will get cycles as group leader no?
>
> AFAIK non-group events are treated as a leader of its own group.
> So evsel__is_group_leader() will return true for cache-misses.
right, then it's fine
thanks,
jirka
