linux-kernel - [tip:perf/core] Revert "perf: Do not allow optimized switch for non-cloned events"

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Date:	Wed, 24 Sep 2014 07:58:43 -0700
From:	tip-bot for Jiri Olsa <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, eranian@...gle.com, hpa@...or.com,
	mingo@...nel.org, jolsa@...nel.org, torvalds@...ux-foundation.org,
	peterz@...radead.org, acme@...nel.org, jolsa@...hat.com,
	fweisbec@...il.com, tglx@...utronix.de
Subject: [tip:perf/core] Revert "perf:
  Do not allow optimized switch for non-cloned events"

Commit-ID:  802c8a61d4c9c794db863dcabb0006ab001a651b
Gitweb:     http://git.kernel.org/tip/802c8a61d4c9c794db863dcabb0006ab001a651b
Author:     Jiri Olsa <jolsa@...hat.com>
AuthorDate: Fri, 12 Sep 2014 13:18:28 +0200
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 24 Sep 2014 14:48:13 +0200

Revert "perf: Do not allow optimized switch for non-cloned events"

This reverts commit 1f9a7268c67f0290837aada443d28fd953ddca90.

With the fix of the initial state for the cloned event we now correctly
handle the error described in:

  1f9a7268c67f perf: Do not allow optimized switch for non-cloned events

so we can revert it.

I made an automated test for this, but its not suitable for automated
perf tests framework. It needs to be customized for each machine (the
more cpu the higher numbers for GROUPS/WORKERS/BYTES) and it could take
longer time to hit the issue.

Signed-off-by: Jiri Olsa <jolsa@...nel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Stephane Eranian <eranian@...gle.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Arnaldo Carvalho de Melo <acme@...nel.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Link: http://lkml.kernel.org/r/20140910143535.GD2409@krava.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 kernel/events/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 132524c..b164cb0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2375,7 +2375,7 @@ static void perf_event_context_sched_out(struct task_struct *task, int ctxn,
 	next_parent = rcu_dereference(next_ctx->parent_ctx);
 
 	/* If neither context have a parent context; they cannot be clones. */
-	if (!parent || !next_parent)
+	if (!parent && !next_parent)
 		goto unlock;
 
 	if (next_parent == ctx || next_ctx == parent || next_parent == parent) {
--
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