linux-kernel - [PATCH 2/3] Revert 'perf evlist: Fix creation of cpu map'

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Date:	Wed, 16 May 2012 18:45:48 +0900
From:	Namhyung Kim <namhyung.kim@....com>
To:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Namhyung Kim <namhyung@...il.com>,
	LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 2/3] Revert 'perf evlist: Fix creation of cpu map'

The commit 55261f46702c ("perf evlist: Fix creation of cpu
map") changed to create a per-task event when no cpu target
is specified. However it caused a problem since perf-task do
not allow event inheritance due to scalability issues so
that the result will contain samples only from parent, not
from its children.

So we should use perf-task-per-cpu events anyway to get the
right result. Revert it.

Reported-by: Linus Torvalds <torvalds@...ux-foundation.org>
Analysed-by: Ingo Molnar <mingo@...nel.org>
Acked-and-tested-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Signed-off-by: Namhyung Kim <namhyung.kim@....com>
---
 tools/perf/util/evlist.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 80bef281eee0..87889f325678 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -609,10 +609,10 @@ int perf_evlist__create_maps(struct perf_evlist *evlist,
 	if (evlist->threads == NULL)
 		return -1;
 
-	if (perf_target__has_cpu(target))
-		evlist->cpus = cpu_map__new(target->cpu_list);
-	else
+	if (perf_target__has_task(target))
 		evlist->cpus = cpu_map__dummy_new();
+	else
+		evlist->cpus = cpu_map__new(target->cpu_list);
 
 	if (evlist->cpus == NULL)
 		goto out_delete_threads;
-- 
1.7.10.1

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