From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f199.google.com (mail-pl1-f199.google.com [209.85.214.199]) by kanga.kvack.org (Postfix) with ESMTP id 10CDA6B027C for ; Sat, 10 Nov 2018 17:43:19 -0500 (EST) Received: by mail-pl1-f199.google.com with SMTP id b4-v6so1236725plb.3 for ; Sat, 10 Nov 2018 14:43:19 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id q13-v6si11684006pgq.526.2018.11.10.14.43.17 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sat, 10 Nov 2018 14:43:17 -0800 (PST) Date: Sat, 10 Nov 2018 15:20:23 +0100 From: Peter Zijlstra Subject: Re: [RFC PATCH 07/12] locking/lockdep: Add support for nested terminal locks Message-ID: <20181110142023.GG3339@worktop.programming.kicks-ass.net> References: <1541709268-3766-1-git-send-email-longman@redhat.com> <1541709268-3766-8-git-send-email-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1541709268-3766-8-git-send-email-longman@redhat.com> Sender: owner-linux-mm@kvack.org List-ID: To: Waiman Long Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, Petr Mladek , Sergey Senozhatsky , Andrey Ryabinin , Tejun Heo , Andrew Morton On Thu, Nov 08, 2018 at 03:34:23PM -0500, Waiman Long wrote: > There are use cases where we want to allow 2-level nesting of one > terminal lock underneath another one. So the terminal lock type is now > extended to support a new nested terminal lock where it can allow the > acquisition of another regular terminal lock underneath it. You're stretching things here... If you're allowing things under it, it is no longer a terminal lock. Why would you want to do such a thing?