From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756131AbdDMJNF (ORCPT ); Thu, 13 Apr 2017 05:13:05 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:57589 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745AbdDMJM7 (ORCPT ); Thu, 13 Apr 2017 05:12:59 -0400 Date: Thu, 13 Apr 2017 11:12:48 +0200 From: Peter Zijlstra To: "Paul E. McKenney" Cc: 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 Message-ID: <20170413091248.xnctlppstkrm6eq5@hirez.programming.kicks-ass.net> References: <20170412165441.GA17149@linux.vnet.ibm.com> <1492016149-18834-1-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1492016149-18834-1-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?