Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754079AbdDMQAh (ORCPT ); Thu, 13 Apr 2017 12:00:37 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49890 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752468AbdDMQAe (ORCPT ); Thu, 13 Apr 2017 12:00:34 -0400 Date: Thu, 13 Apr 2017 09:00:27 -0700 From: "Paul E. McKenney" To: Vlastimil Babka Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , linux-mm@kvack.org Subject: Re: [PATCH tip/core/rcu 01/13] mm: Rename SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU Reply-To: paulmck@linux.vnet.ibm.com References: <20170412165441.GA17149@linux.vnet.ibm.com> <1492016149-18834-1-git-send-email-paulmck@linux.vnet.ibm.com> <20170413091248.xnctlppstkrm6eq5@hirez.programming.kicks-ass.net> <50d59b9c-fa8e-1992-2613-e84774ec5428@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50d59b9c-fa8e-1992-2613-e84774ec5428@suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17041316-0052-0000-0000-000001D5EA10 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006929; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00847050; UDB=6.00417876; IPR=6.00625484; BA=6.00005288; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015033; XFM=3.00000013; UTC=2017-04-13 16:00:32 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17041316-0053-0000-0000-00004FEC3509 Message-Id: <20170413160027.GX3956@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-13_11:,, 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=8.0.1-1702020001 definitions=main-1704130136 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 35 On Thu, Apr 13, 2017 at 01:06:56PM +0200, Vlastimil Babka wrote: > On 04/13/2017 11:12 AM, Peter Zijlstra wrote: > > On Wed, Apr 12, 2017 at 09:55:37AM -0700, Paul E. McKenney wrote: > >> A group of Linux kernel hackers reported chasing a bug that resulted > >> from their assumption that SLAB_DESTROY_BY_RCU provided an existence > >> guarantee, that is, that no block from such a slab would be reallocated > >> during an RCU read-side critical section. Of course, that is not the > >> case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire > >> slab of blocks. > > > > And that while we wrote a huge honking comment right along with it... > > > >> [ paulmck: Add "tombstone" comments as requested by Eric Dumazet. ] > > > > I cannot find any occurrence of "tomb" or "TOMB" in the actual patch, > > confused? > > It's the comments such as: > > + * Note that SLAB_TYPESAFE_BY_RCU was originally named SLAB_DESTROY_BY_RCU. > > so that people who remember the old name can git grep its fate. Exactly! But I must confess that "tombstone" was an excessively obscure word choice, even for native English speakers. I have reworded as follows: [ paulmck: Add comments mentioning the old name, as requested by Eric Dumazet, in order to help people familiar with the old name find the new one. ] Does that help? Thanx, Paul