Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751270AbdH1G4D (ORCPT ); Mon, 28 Aug 2017 02:56:03 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:32874 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751669AbdH1G4A (ORCPT ); Mon, 28 Aug 2017 02:56:00 -0400 Date: Mon, 28 Aug 2017 08:55:53 +0200 From: Peter Zijlstra To: Byungchul Park Cc: tj@kernel.org, johannes.berg@intel.com, mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, kernel-team@lge.com Subject: Re: [RFC] workqueue: remove manual lockdep uses to detect deadlocks Message-ID: <20170828065553.gikwc5zsuy2762eg@hirez.programming.kicks-ass.net> References: <1503650463-14582-1-git-send-email-byungchul.park@lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1503650463-14582-1-git-send-email-byungchul.park@lge.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 981 Lines: 25 On Fri, Aug 25, 2017 at 05:41:03PM +0900, Byungchul Park wrote: > Hello all, > > This is _RFC_. > > I want to request for comments about if it's reasonable conceptually. If > yes, I want to resend after working it more carefully. > > Could you let me know your opinions about this? > > ----->8----- > From 448360c343477fff63df766544eec4620657a59e Mon Sep 17 00:00:00 2001 > From: Byungchul Park > Date: Fri, 25 Aug 2017 17:35:07 +0900 > Subject: [RFC] workqueue: remove manual lockdep uses to detect deadlocks > > We introduced the following commit to detect deadlocks caused by > wait_for_completion() in flush_{workqueue, work}() and other locks. But > now LOCKDEP_COMPLETIONS is introduced, such works are automatically done > by LOCKDEP_COMPLETIONS. So it doesn't have to be done manually anymore. > Removed it. > No.. the existing annotation is strictly better because it will _always_ warn. It doesn't need to first observe things just right.