perf tools: Fix generation of pmu list

The internal pmu list was never used. With each perf_pmu__find() call
the pmu structure was created new by parsing sysfs. Beside this it
caused memory leaks. We now keep all pmus by adding them to the list.

Also, pmu_lookup() should return pmus that do not expose the format
specifier in sysfs.

We need a valid internal pmu list in a later patch to iterate over all
pmus that exist in the system.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1339706321-8802-3-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/pmu.c

@@ -72,7 +72,7 @@ static int pmu_format(char *name, struct list_head *format)
 		 "%s/bus/event_source/devices/%s/format", sysfs, name);
 
 	if (stat(path, &st) < 0)
-		return -1;
+		return 0;	/* no error if format does not exist */
 
 	if (pmu_format_parse(path, format))
 		return -1;
@@ -252,6 +252,7 @@ static struct perf_pmu *pmu_lookup(char *name)
 	list_splice(&aliases, &pmu->aliases);
 	pmu->name = strdup(name);
 	pmu->type = type;
+	list_add_tail(&pmu->list, &pmus);
 	return pmu;
 }