Hi David, On Sat, Dec 27, 2014 at 1:27 AM, David Ahern <dsah...@gmail.com> wrote: > On 12/24/14 12:14 AM, Namhyung Kim wrote: >> >> Prepend a software dummy event into evlist to track task/comm/mmap >> events separately. This is a preparation of multi-file/thread support >> which will come later. > > > Are you are making this the first event because of how perf internals are > coded -- that the first event tracks tasks events? With the tracking bit in > evsel you should not need to do that. Is there another reason?
Yeah, I know the tracking bit can be set to any evsel in the evlist. But I'd like to keep it at a fixed index so that it can be easily identified at later stages (like perf report) too. Ideally, it'd be great if we have a way to distinguish this auto-added dummy tracking event from other (user-added) (dummy?) tracking events if any. > > ---8<--- > >> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c >> index cfbe2b99b9aa..72dff295237e 100644 >> --- a/tools/perf/util/evlist.c >> +++ b/tools/perf/util/evlist.c >> @@ -193,6 +193,44 @@ int perf_evlist__add_default(struct perf_evlist >> *evlist) >> return -ENOMEM; >> } >> >> +int perf_evlist__prepend_dummy(struct perf_evlist *evlist) >> +{ >> + struct perf_event_attr attr = { >> + .type = PERF_TYPE_SOFTWARE, >> + .config = PERF_COUNT_SW_DUMMY, >> + }; >> + struct perf_evsel *evsel, *pos; >> + >> + event_attr_init(&attr); >> + >> + evsel = perf_evsel__new(&attr); >> + if (evsel == NULL) >> + goto error; >> + >> + /* use strdup() because free(evsel) assumes name is allocated */ >> + evsel->name = strdup("dummy"); >> + if (!evsel->name) >> + goto error_free; >> + >> + list_for_each_entry(pos, &evlist->entries, node) { >> + pos->idx += 1; >> + pos->tracking = false; >> + } >> + >> + list_add(&evsel->node, &evlist->entries); >> + evsel->idx = 0; >> + evsel->tracking = true; > > > perf_evlist__set_tracking_event()? I found that after I wrote this, so yes, it can use the function instead of the oped-code. But the loop traversal is needed anyway to fixup the evsel->idx. Thanks, Namhyung -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/