From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750995AbWAJNId (ORCPT ); Tue, 10 Jan 2006 08:08:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750959AbWAJNId (ORCPT ); Tue, 10 Jan 2006 08:08:33 -0500 Received: from mail.tv-sign.ru ([213.234.233.51]:56747 "EHLO several.ru") by vger.kernel.org with ESMTP id S1750995AbWAJNIc (ORCPT ); Tue, 10 Jan 2006 08:08:32 -0500 Message-ID: <43C3C3B5.61D5641@tv-sign.ru> Date: Tue, 10 Jan 2006 17:24:53 +0300 From: Oleg Nesterov X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.2.20 i686) X-Accept-Language: en MIME-Version: 1.0 To: vatsa@in.ibm.com Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, Dipankar Sarma , Manfred Spraul , Linus Torvalds , Andrew Morton Subject: [PATCH] rcu: fix hotplug-cpu ->donelist leak References: <43C165BC.F7C6DCF5@tv-sign.ru> <20060109185944.GB15083@us.ibm.com> <43C2C818.65238C30@tv-sign.ru> <20060109195933.GE14738@us.ibm.com> <20060110095811.GA30159@in.ibm.com> Content-Type: text/plain; charset=koi8-r Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Pointed out by Srivatsa Vaddagiri . rcu_do_batch() stops after processing maxbatch callbacks on ->donelist leaving rcu_tasklet in TASKLET_STATE_SCHED state. If CPU_DEAD event happens remaining ->donelist entries are lost, rcu_offline_cpu() kills this tasklet. With this patch ->donelist migrates along with ->curlist and ->nxtlist to the current cpu. Compile tested. Signed-off-by: Oleg Nesterov --- 2.6.15/kernel/rcupdate.c~4_HPFIX 2006-01-10 19:06:38.000000000 +0300 +++ 2.6.15/kernel/rcupdate.c 2006-01-10 19:15:01.000000000 +0300 @@ -343,8 +343,9 @@ static void __rcu_offline_cpu(struct rcu spin_unlock_bh(&rcp->lock); rcu_move_batch(this_rdp, rdp->curlist, rdp->curtail); rcu_move_batch(this_rdp, rdp->nxtlist, rdp->nxttail); - + rcu_move_batch(this_rdp, rdp->donelist, rdp->donetail); } + static void rcu_offline_cpu(int cpu) { struct rcu_data *this_rdp = &get_cpu_var(rcu_data);