From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754154AbbIJCLx (ORCPT ); Wed, 9 Sep 2015 22:11:53 -0400 Received: from g1t6225.austin.hp.com ([15.73.96.126]:42196 "EHLO g1t6225.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752102AbbIJCLt (ORCPT ); Wed, 9 Sep 2015 22:11:49 -0400 Message-ID: <55F0E592.4050901@hpe.com> Date: Wed, 09 Sep 2015 22:06:10 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Peter Zijlstra CC: Linus Torvalds , Dave Chinner , Linux Kernel Mailing List , Waiman Long , Ingo Molnar Subject: Re: [4.2, Regression] Queued spinlocks cause major XFS performance regression References: <20150904054820.GY3902@dastard> <20150904071143.GZ3902@dastard> <20150904082954.GB3902@dastard> <20150904151427.GG18489@twins.programming.kicks-ass.net> <20150904153035.GH18489@twins.programming.kicks-ass.net> <20150904155448.GS18673@twins.programming.kicks-ass.net> In-Reply-To: <20150904155448.GS18673@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/04/2015 11:54 AM, Peter Zijlstra wrote: > On Fri, Sep 04, 2015 at 05:30:35PM +0200, Peter Zijlstra wrote: >> Should I place the virt_spin_lock() thing under CONFIG_PARAVIRT (maybe >> even _SPINLOCKS) such that only paravirt enabled kernels when ran on a >> hypervisor that does not support paravirt patching (HyperV, VMware, >> etc..) revert to the test-and-set? > Ah, CONFIG_HYPERVISOR_GUEST seems fitting, that's a prerequisite for all > the PARAVIRT options too. > Yes, I also used that in my queued unfair lock patch. Cheers, Longman