From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH 05/11] qspinlock: Optimize for smaller NR_CPUS Date: Wed, 18 Jun 2014 13:39:52 +0200 Message-ID: <53A17A88.7090705@redhat.com> References: <20140615124657.264658593@chello.nl> <20140615130153.483502389@chello.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140615130153.483502389@chello.nl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Peter Zijlstra , Waiman.Long@hp.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-arch@vger.kernel.org, riel@redhat.com, gleb@redhat.com, kvm@vger.kernel.org, konrad.wilk@oracle.com, Peter Zijlstra , scott.norton@hp.com, raghavendra.kt@linux.vnet.ibm.com, paolo.bonzini@gmail.com, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, chegu_vinod@hp.com, david.vrabel@citrix.com, oleg@redhat.com, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com, paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org List-Id: linux-arch.vger.kernel.org Il 15/06/2014 14:47, Peter Zijlstra ha scritto: > > - for (;;) { > - new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL; > - > - old = atomic_cmpxchg(&lock->val, val, new); > - if (old == val) > - break; > - > - val = old; > - } > + clear_pending_set_locked(lock, val); > return; Might as well add clear_pending_set_locked already in patch 3. Paolo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:45127 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966054AbaFRLkr (ORCPT ); Wed, 18 Jun 2014 07:40:47 -0400 Message-ID: <53A17A88.7090705@redhat.com> Date: Wed, 18 Jun 2014 13:39:52 +0200 From: Paolo Bonzini MIME-Version: 1.0 Subject: Re: [PATCH 05/11] qspinlock: Optimize for smaller NR_CPUS References: <20140615124657.264658593@chello.nl> <20140615130153.483502389@chello.nl> In-Reply-To: <20140615130153.483502389@chello.nl> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra , Waiman.Long@hp.com, tglx@linutronix.de, mingo@kernel.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, xen-devel@lists.xenproject.org, kvm@vger.kernel.org, paolo.bonzini@gmail.com, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, paulmck@linux.vnet.ibm.com, riel@redhat.com, torvalds@linux-foundation.org, raghavendra.kt@linux.vnet.ibm.com, david.vrabel@citrix.com, oleg@redhat.com, gleb@redhat.com, scott.norton@hp.com, chegu_vinod@hp.com, Peter Zijlstra Message-ID: <20140618113952.GDn1pjuhMktXk3FvlzFZob3cXsvWibnyC1pzrPMLnyU@z> Il 15/06/2014 14:47, Peter Zijlstra ha scritto: > > - for (;;) { > - new = (val & ~_Q_PENDING_MASK) | _Q_LOCKED_VAL; > - > - old = atomic_cmpxchg(&lock->val, val, new); > - if (old == val) > - break; > - > - val = old; > - } > + clear_pending_set_locked(lock, val); > return; Might as well add clear_pending_set_locked already in patch 3. Paolo