From: Peter Zijlstra Subject: Re: [PATCH v2 08/17] locking/lockdep: Add support for nestable terminal locks Date: Fri, 7 Dec 2018 10:22:52 +0100 Message-ID: <20181207092252.GF2237@hirez.programming.kicks-ass.net> References: <1542653726-5655-1-git-send-email-longman@redhat.com> <1542653726-5655-9-git-send-email-longman@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1542653726-5655-9-git-send-email-longman@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Waiman Long Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, iommu@lists.linux-foundation.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton List-Id: iommu@lists.linux-foundation.org On Mon, Nov 19, 2018 at 01:55:17PM -0500, Waiman Long wrote: > There are use cases where we want to allow nesting of one terminal lock > underneath another terminal-like lock. That new lock type is called > nestable terminal lock which can optionally allow the acquisition of > no more than one regular (non-nestable) terminal lock underneath it. I think I asked for a more coherent changelog on this. The above is still self contradictory and doesn't explain why you'd ever want such a 'misfeature' :-)