From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935115AbcATKxK (ORCPT ); Wed, 20 Jan 2016 05:53:10 -0500 Received: from casper.infradead.org ([85.118.1.10]:54204 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757921AbcATKxG (ORCPT ); Wed, 20 Jan 2016 05:53:06 -0500 Date: Wed, 20 Jan 2016 11:53:02 +0100 From: Peter Zijlstra To: Christian Borntraeger Cc: Heiko Carstens , Tejun Heo , "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , linux-s390 , KVM list , Oleg Nesterov , "Paul E. McKenney" Subject: Re: regression 4.4: deadlock in with cgroup percpu_rwsem Message-ID: <20160120105302.GE6373@twins.programming.kicks-ass.net> References: <5698A023.9070703@de.ibm.com> <56990C9E.7020801@de.ibm.com> <20160118183205.GW6357@twins.programming.kicks-ass.net> <569D3370.6040503@de.ibm.com> <20160119095518.GC3528@osiris> <569E9032.3070903@de.ibm.com> <20160119193845.GT3520@mtj.duckdns.org> <20160120070740.GA3395@osiris> <569F5E29.3090107@de.ibm.com> <20160120103036.GJ6357@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160120103036.GJ6357@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 20, 2016 at 11:30:36AM +0100, Peter Zijlstra wrote: > On Wed, Jan 20, 2016 at 11:15:05AM +0100, Christian Borntraeger wrote: > > [ 561.044066] Krnl PSW : 0704e00180000000 00000000001aa1ee (remove_entity_load_avg+0x1e/0x1b8) > > > [ 561.044176] ([<00000000001ad750>] free_fair_sched_group+0x80/0xf8) > > [ 561.044181] [<0000000000192656>] free_sched_group+0x2e/0x58 > > [ 561.044187] [<00000000001ded82>] rcu_process_callbacks+0x3fa/0x928 > > Urgh,.. lemme stare at that. Christian, can you test with the remove_entity_load_avg() call removed from free_fair_sched_group() ? It will slightly mess up accounting, but should be non fatal and avoids this current issue. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: regression 4.4: deadlock in with cgroup percpu_rwsem Date: Wed, 20 Jan 2016 11:53:02 +0100 Message-ID: <20160120105302.GE6373@twins.programming.kicks-ass.net> References: <5698A023.9070703@de.ibm.com> <56990C9E.7020801@de.ibm.com> <20160118183205.GW6357@twins.programming.kicks-ass.net> <569D3370.6040503@de.ibm.com> <20160119095518.GC3528@osiris> <569E9032.3070903@de.ibm.com> <20160119193845.GT3520@mtj.duckdns.org> <20160120070740.GA3395@osiris> <569F5E29.3090107@de.ibm.com> <20160120103036.GJ6357@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160120103036.GJ6357@twins.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Christian Borntraeger Cc: Heiko Carstens , Tejun Heo , "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , linux-s390 , KVM list , Oleg Nesterov , "Paul E. McKenney" List-ID: On Wed, Jan 20, 2016 at 11:30:36AM +0100, Peter Zijlstra wrote: > On Wed, Jan 20, 2016 at 11:15:05AM +0100, Christian Borntraeger wrote: > > [ 561.044066] Krnl PSW : 0704e00180000000 00000000001aa1ee (remove_entity_load_avg+0x1e/0x1b8) > > > [ 561.044176] ([<00000000001ad750>] free_fair_sched_group+0x80/0xf8) > > [ 561.044181] [<0000000000192656>] free_sched_group+0x2e/0x58 > > [ 561.044187] [<00000000001ded82>] rcu_process_callbacks+0x3fa/0x928 > > Urgh,.. lemme stare at that. Christian, can you test with the remove_entity_load_avg() call removed from free_fair_sched_group() ? It will slightly mess up accounting, but should be non fatal and avoids this current issue.