From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754939AbbAOTju (ORCPT ); Thu, 15 Jan 2015 14:39:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46890 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751900AbbAOTjs (ORCPT ); Thu, 15 Jan 2015 14:39:48 -0500 Date: Thu, 15 Jan 2015 20:38:39 +0100 From: Oleg Nesterov To: Christian Borntraeger Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, xen-devel@lists.xenproject.org, linux-mm@kvack.org Subject: Re: [PATCH 4/8] x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE Message-ID: <20150115193839.GA28727@redhat.com> References: <1421312314-72330-1-git-send-email-borntraeger@de.ibm.com> <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/15, Christian Borntraeger wrote: > > --- a/arch/x86/include/asm/spinlock.h > +++ b/arch/x86/include/asm/spinlock.h > @@ -186,7 +186,7 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock) > __ticket_t head = ACCESS_ONCE(lock->tickets.head); > > for (;;) { > - struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets); > + struct __raw_tickets tmp = READ_ONCE(lock->tickets); Agreed, but what about another ACCESS_ONCE() above? Oleg.