perf evlist: Return first evsel for non-sample event on old kernel
authorNamhyung Kim <namhyung.kim@lge.com>
Mon, 20 Feb 2012 01:47:26 +0000 (10:47 +0900)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 29 Feb 2012 21:29:44 +0000 (18:29 -0300)
commit30e68bcc67e41ab6dab4e4e1efc7ea8ca893c0af
tree49934bc86d7df5a86311a1123c08f3a389e8b2aa
parent30ce2f7eef095d1b8d070740f1948629814fe3c7
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>
tools/perf/util/evlist.c