From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932418AbdJJQfj (ORCPT ); Tue, 10 Oct 2017 12:35:39 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:41698 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932075AbdJJQfg (ORCPT ); Tue, 10 Oct 2017 12:35:36 -0400 Date: Tue, 10 Oct 2017 09:35:32 -0700 From: "Paul E. McKenney" To: Mark Rutland Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 13/13] rcutorture: formal: prepare for ACCESS_ONCE() removal Reply-To: paulmck@linux.vnet.ibm.com References: <1507573730-8083-1-git-send-email-mark.rutland@arm.com> <1507573730-8083-14-git-send-email-mark.rutland@arm.com> <20171009195112.GL3521@linux.vnet.ibm.com> <20171010095413.GE27659@leverpostej> <20171010124712.GV3521@linux.vnet.ibm.com> <20171010125039.GI27659@leverpostej> <20171010145252.GX3521@linux.vnet.ibm.com> <20171010162441.GM27659@leverpostej> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171010162441.GM27659@leverpostej> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17101016-0048-0000-0000-000001F380AE X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007873; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000235; SDB=6.00929181; UDB=6.00467660; IPR=6.00709452; BA=6.00005632; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017476; XFM=3.00000015; UTC=2017-10-10 16:35:34 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17101016-0049-0000-0000-000042D3719F Message-Id: <20171010163532.GL3521@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-10_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710100235 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 10, 2017 at 05:24:42PM +0100, Mark Rutland wrote: > On Tue, Oct 10, 2017 at 07:52:52AM -0700, Paul E. McKenney wrote: > > On Tue, Oct 10, 2017 at 01:50:39PM +0100, Mark Rutland wrote: > > > On Tue, Oct 10, 2017 at 05:47:12AM -0700, Paul E. McKenney wrote: > > > > On Tue, Oct 10, 2017 at 10:54:14AM +0100, Mark Rutland wrote: > > > > > > I've assumed that the ACCESS_ONCE() definition needs to be kept until > > > > > that's ripped out treewide. Please shout if that's not the case! > > > > > > > > You have it right. This case is an exception because this code is > > > > used only by RCU, which has long since had ACCESS_ONCE() ripped out. > > > > > > Sorry; I meant that in this case, I leave this code as: > > > > > > #define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x)) > > > #define READ_ONCE(x) (*(volatile typeof(x) *) &(x)) > > > #define WRITE_ONCE(x) ((*(volatile typeof(x) *) &(x)) = (val)) > > > > > > ... if you mean that we can drop ACCESS_ONCE() in this case, then I can > > > rip that out. > > > > We can drop ACCESS_ONCE() in this case. > > Done. Sorry for the confusion! Very good, thank you! Thanx, Paul