From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938317AbeBURxv (ORCPT ); Wed, 21 Feb 2018 12:53:51 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39436 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938248AbeBURxs (ORCPT ); Wed, 21 Feb 2018 12:53:48 -0500 Date: Wed, 21 Feb 2018 09:53:53 -0800 From: "Paul E. McKenney" To: Ingo Molnar Cc: Alan Stern , Andrea Parri , Akira Yokosawa , Kernel development list , Will Deacon , peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, Jade Alglave , Luc Maranget , Patrick Bellasi Subject: Re: [PATCH] tools/memory-model: remove rb-dep, smp_read_barrier_depends, and lockless_dereference Reply-To: paulmck@linux.vnet.ibm.com References: <20180217003959.GR3617@linux.vnet.ibm.com> <20180221160602.GD3617@linux.vnet.ibm.com> <20180221165143.gf5hhhrddediubdx@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180221165143.gf5hhhrddediubdx@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 18022117-0048-0000-0000-0000023CFB8D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008571; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.00993054; UDB=6.00504563; IPR=6.00772398; MB=3.00019675; MTD=3.00000008; XFM=3.00000015; UTC=2018-02-21 17:53:46 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022117-0049-0000-0000-000044354AF7 Message-Id: <20180221175353.GJ3617@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-21_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802210216 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 21, 2018 at 05:51:43PM +0100, Ingo Molnar wrote: > > * Paul E. McKenney wrote: > > > On Wed, Feb 21, 2018 at 10:00:20AM -0500, Alan Stern wrote: > > > On Fri, 16 Feb 2018, Paul E. McKenney wrote: > > > > > > > On Fri, Feb 16, 2018 at 05:22:55PM -0500, Alan Stern wrote: > > > > > Since commit 76ebbe78f739 ("locking/barriers: Add implicit > > > > > smp_read_barrier_depends() to READ_ONCE()") was merged for the 4.15 > > > > > kernel, it has not been necessary to use smp_read_barrier_depends(). > > > > > Similarly, commit 59ecbbe7b31c ("locking/barriers: Kill > > > > > lockless_dereference()") removed lockless_dereference() from the > > > > > kernel. > > > > > > > > > > Since these primitives are no longer part of the kernel, they do not > > > > > belong in the Linux Kernel Memory Consistency Model. This patch > > > > > removes them, along with the internal rb-dep relation, and updates the > > > > > revelant documentation. > > > > > > > > > > Signed-off-by: Alan Stern > > > > > > > > I queued this, but would welcome an update that addressed Akira's > > > > feedback as appropriate. > > > > > > Is it too late to send a v2 of this patch? I didn't want to do it > > > before now because the issue raised by Andrea wasn't settled. (Some > > > could claim that it still isn't fully settled...) > > > > Would you be willing to send a delta patch? I can then place it directly > > on top of your original patch, and once it settles out, I can ask Ingo > > if he is willing to update the patch in -tip. > > It would be better to have followup fixes as separate patches. I applied the > current set of fixes/improvements today to help move things along - it's all > advancing very nicely! Will do, and glad you like it! Thanx, Paul