From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754406AbdJINIo (ORCPT ); Mon, 9 Oct 2017 09:08:44 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:50797 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754404AbdJINHE (ORCPT ); Mon, 9 Oct 2017 09:07:04 -0400 X-Google-Smtp-Source: AOwi7QDEHFzM+lppbkYuu6kYwuCXsMuxOixBa9fohzfFhxl0VKfBOBgNZFsLEKisuqDSqKPmDMQ/ig== Date: Mon, 9 Oct 2017 06:07:00 -0700 From: Tejun Heo To: Peter Zijlstra Cc: Boqun Feng , linux-kernel@vger.kernel.org, Josef Bacik , Lai Jiangshan Subject: Re: [RFC] workqueue: Fix irq inversion deadlock in manage_workers() Message-ID: <20171009130700.GY3301751@devbig577.frc2.facebook.com> References: <20171008090225.27034-1-boqun.feng@gmail.com> <20171008190109.GX3301751@devbig577.frc2.facebook.com> <20171009064257.43lfvc4ey7xrr7hz@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171009064257.43lfvc4ey7xrr7hz@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 Mon, Oct 09, 2017 at 08:42:57AM +0200, Peter Zijlstra wrote: > On Sun, Oct 08, 2017 at 12:03:47PM -0700, Tejun Heo wrote: > > So, if I'm not mistaken, this is a regression caused by b9c16a0e1f73 > > ("locking/mutex: Fix lockdep_assert_held() fail") which seems to > > replace irqsave operations inside mutex to unconditional irq ones. > > No, it existed before that. You're looking at the DEBUG_MUTEX case, the > normal case looked like: Ah, I see. That mutex usage was a stretch anyway. I'll get rid of it. Thanks. -- tejun