From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751272AbdHXGMA (ORCPT ); Thu, 24 Aug 2017 02:12:00 -0400 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:40859 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111AbdHXGL7 (ORCPT ); Thu, 24 Aug 2017 02:11:59 -0400 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Thu, 24 Aug 2017 15:11:53 +0900 From: Byungchul Park To: Peter Zijlstra Cc: Oleg Nesterov , mingo@kernel.org, linux-kernel@vger.kernel.org, kernel-team@lge.com, Arnaldo Carvalho de Melo , Dave Chinner , Tejun Heo , johannes@sipsolutions.net Subject: Re: [PATCH v3 1/3] lockdep: Make LOCKDEP_CROSSRELEASE configs all part of PROVE_LOCKING Message-ID: <20170824061153.GF6772@X58A-UD3R> References: <20170822051438.GD20323@X58A-UD3R> <20170822075238.uyfmhgxeal2bwcdg@hirez.programming.kicks-ass.net> <20170822085100.GH20323@X58A-UD3R> <20170822092141.fjmr74xhfid7vu7h@hirez.programming.kicks-ass.net> <20170822093337.GJ20323@X58A-UD3R> <20170822100840.eababgjcu76iois5@hirez.programming.kicks-ass.net> <20170822134922.m2g6kqsqo2eojrg7@hirez.programming.kicks-ass.net> <20170822144602.uh5jzkkchvdgzs3s@hirez.programming.kicks-ass.net> <20170823163903.GA12973@redhat.com> <20170823174714.in4mv7uc3rdheygg@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170823174714.in4mv7uc3rdheygg@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 23, 2017 at 07:47:14PM +0200, Peter Zijlstra wrote: > Those are fine and are indeed the flush_work() vs work inversion. > > The two straight forward annotations are: > > flush_work(work) process_one_work(wq, work) > A(work) A(work) > R(work) work->func(work); > R(work) > > Which catches: > > Task-1: work: > > mutex_lock(&A); mutex_lock(&A); > flush_work(work); I'm not sure but, with LOCKDEP_COMPLETE enabled, this issue would automatically be covered w/o additional A(work)/R(work). Right? A(work)/R(work) seem to be used for preventing wait_for_completion() in flush_work() from waiting for the completion forever because of the work using mutex_lock(&A). Am I understanding correctly? If yes, we can use just LOCKDEP_COMPLETE for that purpose. > And the analogous: > > flush_workqueue(wq) process_one_work(wq, work) > A(wq) A(wq) > R(wq) work->func(work); > (wq)