Commit 30e68bcc authored Feb 20, 2012 by Namhyung Kim Committed by Arnaldo Carvalho de Melo Feb 29, 2012

perf evlist: Return first evsel for non-sample event on old kernel



On old kernels that don't support sample_id_all feature,
perf_evlist__id2evsel() returns NULL for non-sampling events.

This breaks perf top when multiple events are given on command line. Fix
it by using first evsel in the evlist. This will also prevent getting
the same (potential) problem in such new tool/ old kernel combo.

Suggested-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1329702447-25045-1-git-send-email-namhyung.kim@lge.com


Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 30ce2f7e

tools/perf/util/evlist.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -349,6 +349,10 @@ struct perf_evsel perf_evlist__id2evsel(struct perf_evlist evlist, u64 id)
		hlist_for_each_entry(sid, pos, head, node)
		if (sid->id == id)
		return sid->evsel;

		if (!perf_evlist__sample_id_all(evlist))
		return list_entry(evlist->entries.next, struct perf_evsel, node);

		return NULL;
		}

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