From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819Ab0FOWaP (ORCPT ); Tue, 15 Jun 2010 18:30:15 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:60603 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753519Ab0FOW3t (ORCPT ); Tue, 15 Jun 2010 18:29:49 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, Daniel J Blueman , "Paul E. McKenney" Subject: [PATCH tip/core/urgent 1/3] rcu: fix lockdep splat in wake_affine() Date: Tue, 15 Jun 2010 15:29:41 -0700 Message-Id: <1276640983-14641-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.0.6 In-Reply-To: <20100615222923.GA14571@linux.vnet.ibm.com> References: <20100615222923.GA14571@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel J Blueman With 2.6.35-rc1 and your patch in the context below, we still see "include/linux/cgroup.h:534 invoked rcu_dereference_check() without protection!", so need this additional patch: Acquire read-side RCU lock around task_group() calls, addressing "include/linux/cgroup.h:534 invoked rcu_dereference_check() without protection!" warning. Signed-off-by: Daniel J Blueman Signed-off-by: Paul E. McKenney --- kernel/sched_fair.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index eed35ed..ca56133 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1240,6 +1240,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) * effect of the currently running task from the load * of the current CPU: */ + rcu_read_lock(); if (sync) { tg = task_group(current); weight = current->se.load.weight; @@ -1249,6 +1250,7 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) } tg = task_group(p); + rcu_read_unlock(); weight = p->se.load.weight; /* -- 1.7.0.6