From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753907AbbIPLGo (ORCPT ); Wed, 16 Sep 2015 07:06:44 -0400 Received: from mail-qg0-f47.google.com ([209.85.192.47]:34611 "EHLO mail-qg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753840AbbIPLGl (ORCPT ); Wed, 16 Sep 2015 07:06:41 -0400 Date: Wed, 16 Sep 2015 07:06:37 -0400 From: Tejun Heo To: "Paul E. McKenney" Cc: Christian Borntraeger , Paolo Bonzini , Peter Zijlstra , Ingo Molnar , "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , KVM list , Oleg Nesterov Subject: Re: [4.2] commit d59cfc09c32 (sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem) causes regression for libvirt/kvm Message-ID: <20150916110637.GB17047@htj.duckdns.org> References: <20150915130550.GC16853@twins.programming.kicks-ass.net> <55F81EE2.4090708@de.ibm.com> <55F84A6B.1010207@redhat.com> <55F88991.7040406@de.ibm.com> <20150915212622.GC495@htj.duckdns.org> <20150915213830.GR4029@linux.vnet.ibm.com> <20150915222811.GD495@htj.duckdns.org> <20150915233818.GU4029@linux.vnet.ibm.com> <20150916012415.GC25658@htj.duckdns.org> <20150916043547.GY4029@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150916043547.GY4029@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Sep 15, 2015 at 09:35:47PM -0700, Paul E. McKenney wrote: > > > I am suggesting trying the options and seeing what works best, then > > > working to convince people as needed. > > > > Yeah, sure thing. Let's wait for Christian. > > Indeed. Is there enough benefit to risk jamming this thing into 4.3? > I believe that 4.4 should be a no-brainer. In that case, I'm gonna revert the threadcgroup percpu_rwsem conversion patches through -stable and reapply them for 4.4 merge window. Thanks! -- tejun