From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933577AbaHHVEf (ORCPT ); Fri, 8 Aug 2014 17:04:35 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:41346 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757095AbaHHUxq (ORCPT ); Fri, 8 Aug 2014 16:53:46 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jiri Olsa , Peter Zijlstra , Arnaldo Carvalho de Melo , Paul Mackerras , Frederic Weisbecker , Namhyung Kim , Corey Ashford , David Ahern , Jiri Olsa , Linus Torvalds , Ingo Molnar , Kamal Mostafa Subject: [PATCH 3.13 112/259] perf: Do not allow optimized switch for non-cloned events Date: Fri, 8 Aug 2014 13:38:55 -0700 Message-Id: <1407530482-4483-113-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1407530482-4483-1-git-send-email-kamal@canonical.com> References: <1407530482-4483-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11.6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Olsa commit 1f9a7268c67f0290837aada443d28fd953ddca90 upstream. The context check in perf_event_context_sched_out allows non-cloned context to be part of the optimized schedule out switch. This could move non-cloned context into another workload child. Once this child exits, the context is closed and leaves all original (parent) events in closed state. Any other new cloned event will have closed state and not measure anything. And probably causing other odd bugs. Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras Cc: Frederic Weisbecker Cc: Namhyung Kim Cc: Paul Mackerras Cc: Corey Ashford Cc: David Ahern Cc: Jiri Olsa Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1403598026-2310-2-git-send-email-jolsa@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Kamal Mostafa --- 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 f0a8ac7..f8519d6 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2296,7 +2296,7 @@ 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) { -- 1.9.1