From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754292AbaHAPMY (ORCPT ); Fri, 1 Aug 2014 11:12:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:65118 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738AbaHAPMX (ORCPT ); Fri, 1 Aug 2014 11:12:23 -0400 Date: Fri, 1 Aug 2014 17:09:26 +0200 From: Oleg Nesterov To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, bobby.prani@gmail.com Subject: Re: [PATCH v3 tip/core/rcu 3/9] rcu: Add synchronous grace-period waiting for RCU-tasks Message-ID: <20140801150926.GA845@redhat.com> References: <20140731215445.GA21933@linux.vnet.ibm.com> <1406843709-23396-1-git-send-email-paulmck@linux.vnet.ibm.com> <1406843709-23396-3-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1406843709-23396-3-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/31, Paul E. McKenney wrote: > > +void synchronize_rcu_tasks(void) > +{ > + /* Complain if the scheduler has not started. */ > + rcu_lockdep_assert(!rcu_scheduler_active, > + "synchronize_rcu_tasks called too soon"); > + > + /* Wait for the grace period. */ > + wait_rcu_gp(call_rcu_tasks); > +} Btw, what about CONFIG_PREEMPT=n ? I mean, can't synchronize_rcu_tasks() be synchronize_sched() in this case? Oleg.