From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031650Ab0B1JAF (ORCPT ); Sun, 28 Feb 2010 04:00:05 -0500 Received: from hera.kernel.org ([140.211.167.34]:40419 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031620Ab0B1JAB (ORCPT ); Sun, 28 Feb 2010 04:00:01 -0500 Date: Sun, 28 Feb 2010 08:59:17 GMT From: "tip-bot for Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1267311188-16603-2-git-send-email-paulmck@linux.vnet.ibm.com> References: <1267311188-16603-2-git-send-email-paulmck@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/rcu] rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use Message-ID: Git-Commit-ID: 1883c79a57a5fe25309007590cccb1b2782c41b2 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Sun, 28 Feb 2010 08:59:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1883c79a57a5fe25309007590cccb1b2782c41b2 Gitweb: http://git.kernel.org/tip/1883c79a57a5fe25309007590cccb1b2782c41b2 Author: Paul E. McKenney AuthorDate: Sat, 27 Feb 2010 14:53:08 -0800 Committer: Ingo Molnar CommitDate: Sun, 28 Feb 2010 09:17:42 +0100 rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use It is apparently legal to invoke task_subsys_state() without RCU protection during early boot time. After all, there are no concurrent tasks, so there can be no grace periods completing concurrently. But this does need an Acked-by from the cgroups folks. Located-by: Ingo Molnar Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1267311188-16603-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- include/linux/cgroup.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index c9bbcb2..a73e1ce 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -489,6 +489,7 @@ static inline struct cgroup_subsys_state *task_subsys_state( { return rcu_dereference_check(task->cgroups->subsys[subsys_id], rcu_read_lock_held() || + !rcu_scheduler_active || cgroup_lock_is_held()); }