From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754929AbdJIPaE (ORCPT ); Mon, 9 Oct 2017 11:30:04 -0400 Received: from mail-qt0-f193.google.com ([209.85.216.193]:45050 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754242AbdJIPaC (ORCPT ); Mon, 9 Oct 2017 11:30:02 -0400 X-Google-Smtp-Source: AOwi7QCdAhUICwcyVSgIzfJwWxC7DliLoZI9QxEt82Efh/lv6GDmPmYb0BFV49KVEltCM4RHMuJQPQ== Date: Mon, 9 Oct 2017 08:29:59 -0700 From: Tejun Heo To: Peter Zijlstra Cc: Lai Jiangshan , Boqun Feng , LKML , Josef Bacik , Thomas Gleixner Subject: Re: [RFC] workqueue: Fix irq inversion deadlock in manage_workers() Message-ID: <20171009152959.GE3301751@devbig577.frc2.facebook.com> References: <20171008090225.27034-1-boqun.feng@gmail.com> <20171009152449.yrqcdhvldgptt4zb@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171009152449.yrqcdhvldgptt4zb@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 Hello, On Mon, Oct 09, 2017 at 05:24:49PM +0200, Peter Zijlstra wrote: > So I think we did something similar to the rt_mutex in: > > b4abf91047cf ("rtmutex: Make wait_lock irq safe") > > And I would not be entirely against doing the same for our normal mutex, > but I've not really had time to read/think through this thread. We may want to do that if there are other more valid cases but this workqueue one shouldn't be the reason. It's something which shouldn't have been a mutex from the get-go. Thanks. -- tejun