From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753441AbcERTem (ORCPT ); Wed, 18 May 2016 15:34:42 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:57665 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751513AbcERTek (ORCPT ); Wed, 18 May 2016 15:34:40 -0400 Date: Wed, 18 May 2016 21:34:31 +0200 From: Peter Zijlstra To: Konrad Rzeszutek Wilk Cc: mingo@kernel.org, kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Waiman.Long@hpe.com, dhowells@redhat.com, david.vrabel@citrix.com, pbonzini@redhat.com, xen-devel@lists.xenproject.org Subject: Re: [Xen-devel] [PATCH] x86, locking: Remove ticket (spin)lock implementation Message-ID: <20160518193431.GQ3193@twins.programming.kicks-ass.net> References: <20160518184302.GO3193@twins.programming.kicks-ass.net> <20160518191344.GA9101@char.us.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160518191344.GA9101@char.us.oracle.com> 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, May 18, 2016 at 03:13:44PM -0400, Konrad Rzeszutek Wilk wrote: > On Wed, May 18, 2016 at 08:43:02PM +0200, Peter Zijlstra wrote: > > > > We've unconditionally used the queued spinlock for many releases now. > > Like since 4.2? Yeah, that seems to be the right number. > I don't know of any enterprise distro that is shipping anything > more modern than 4.1? RHEL 7 -- v3.10 SLES 12 -- v3.12 Debian Jessie -- v3.16 Ubuntu 16.04 LTS -- v4.4 But waiting for the major enterprise distros (RHEL/SLES) would mean another decade or so before people start using it. We don't usually wait this long for anything. > Perhaps it would be good to wait until they > at least ship and then give them some time to see if they have found > any issues? My motivation was that people keep trying to send patches against the ticket lock code... David did just today, and he's not the first.