Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933136AbcDYQlV (ORCPT ); Mon, 25 Apr 2016 12:41:21 -0400 Received: from mail-ig0-f173.google.com ([209.85.213.173]:36567 "EHLO mail-ig0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932686AbcDYQlU (ORCPT ); Mon, 25 Apr 2016 12:41:20 -0400 MIME-Version: 1.0 In-Reply-To: <20160425160023.GA7822@mtj.duckdns.org> References: <1461597771-25352-1-git-send-email-roman.penyaev@profitbricks.com> <20160425154847.GZ7822@mtj.duckdns.org> <20160425160023.GA7822@mtj.duckdns.org> From: Roman Penyaev Date: Mon, 25 Apr 2016 18:40:59 +0200 Message-ID: Subject: Re: [PATCH 1/1] [RFC] workqueue: fix ghost PENDING flag while doing MQ IO To: Tejun Heo Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 626 Lines: 15 On Mon, Apr 25, 2016 at 6:00 PM, Tejun Heo wrote: > On Mon, Apr 25, 2016 at 11:48:47AM -0400, Tejun Heo wrote: >> Heh, excellent debugging. I wonder how old this bug is. cc'ing David > > I just went through the history. So, we used to have clear_bit() > instead of atomic_long_set() but clear_bit() doesn't imply any barrier > either, so kudos to you. You just debugged an issue which is most > likely has been there for over a decade! :) That's nice, that we can finally fix it. But as I was saying I was just lucky enough to have very easy reproduction. I could check all crazy ideas I had :) -- Roman