From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966745AbcAZQlY (ORCPT ); Tue, 26 Jan 2016 11:41:24 -0500 Received: from verein.lst.de ([213.95.11.211]:37394 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964834AbcAZQlW (ORCPT ); Tue, 26 Jan 2016 11:41:22 -0500 Date: Tue, 26 Jan 2016 17:41:20 +0100 From: Christoph Hellwig To: Tejun Heo Cc: Christoph Hellwig , "Paul E. McKenney" , Peter Zijlstra , Christian Borntraeger , Heiko Carstens , "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , linux-s390 , KVM list , Oleg Nesterov Subject: Re: regression 4.4: deadlock in with cgroup percpu_rwsem Message-ID: <20160126164120.GA3047@lst.de> References: <20160120070740.GA3395@osiris> <569F5E29.3090107@de.ibm.com> <20160120103036.GJ6357@twins.programming.kicks-ass.net> <20160120104758.GD6373@twins.programming.kicks-ass.net> <20160120153007.GC5157@mtj.duckdns.org> <20160123020313.GA4915@linux.vnet.ibm.com> <20160125084942.GA7354@lst.de> <20160125193836.GH3628@mtj.duckdns.org> <20160126145157.GA31177@lst.de> <20160126152846.GO3628@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160126152846.GO3628@mtj.duckdns.org> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 26, 2016 at 10:28:46AM -0500, Tejun Heo wrote: > Hmmm... why do you need to call percpu_ref_exit() from process > context? All it does is freeing the percpu counter and resetting the > state, both of which can be done from any context. I checked and that's true indeed. You cought me doing cargo cult programming as the callers I looked at already do this. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: regression 4.4: deadlock in with cgroup percpu_rwsem Date: Tue, 26 Jan 2016 17:41:20 +0100 Message-ID: <20160126164120.GA3047@lst.de> References: <20160120070740.GA3395@osiris> <569F5E29.3090107@de.ibm.com> <20160120103036.GJ6357@twins.programming.kicks-ass.net> <20160120104758.GD6373@twins.programming.kicks-ass.net> <20160120153007.GC5157@mtj.duckdns.org> <20160123020313.GA4915@linux.vnet.ibm.com> <20160125084942.GA7354@lst.de> <20160125193836.GH3628@mtj.duckdns.org> <20160126145157.GA31177@lst.de> <20160126152846.GO3628@mtj.duckdns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20160126152846.GO3628@mtj.duckdns.org> Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Tejun Heo Cc: Christoph Hellwig , "Paul E. McKenney" , Peter Zijlstra , Christian Borntraeger , Heiko Carstens , "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , linux-s390 , KVM list , Oleg Nesterov List-ID: On Tue, Jan 26, 2016 at 10:28:46AM -0500, Tejun Heo wrote: > Hmmm... why do you need to call percpu_ref_exit() from process > context? All it does is freeing the percpu counter and resetting the > state, both of which can be done from any context. I checked and that's true indeed. You cought me doing cargo cult programming as the callers I looked at already do this.