From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Date: Thu, 15 Jan 2015 19:38:39 +0000 Subject: Re: [PATCH 4/8] x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE Message-Id: <20150115193839.GA28727@redhat.com> List-Id: References: <1421312314-72330-1-git-send-email-borntraeger@de.ibm.com> <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> In-Reply-To: <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 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. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Subject: Re: [PATCH 4/8] x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE Date: Thu, 15 Jan 2015 20:38:39 +0100 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 Return-path: Content-Disposition: inline In-Reply-To: <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> Sender: owner-linux-mm@kvack.org 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 List-Id: linux-arch.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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> Sender: linux-arch-owner@vger.kernel.org List-ID: 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 Message-ID: <20150115193839.rddqXA26rg7STL10czn0xa1RwgwtoeZHWEm80Ne2L0M@z> 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. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 9210E1A0C21 for ; Fri, 16 Jan 2015 06:39:43 +1100 (AEDT) Date: Thu, 15 Jan 2015 20:38:39 +0100 From: Oleg Nesterov To: Christian Borntraeger 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 In-Reply-To: <1421312314-72330-5-git-send-email-borntraeger@de.ibm.com> Cc: linux-arch@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, xen-devel@lists.xenproject.org, linuxppc-dev@lists.ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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.