Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932999AbcDYQAa (ORCPT ); Mon, 25 Apr 2016 12:00:30 -0400 Received: from mail-yw0-f173.google.com ([209.85.161.173]:33785 "EHLO mail-yw0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932843AbcDYQA0 (ORCPT ); Mon, 25 Apr 2016 12:00:26 -0400 Date: Mon, 25 Apr 2016 12:00:23 -0400 From: Tejun Heo To: Roman Pen Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells Subject: Re: [PATCH 1/1] [RFC] workqueue: fix ghost PENDING flag while doing MQ IO Message-ID: <20160425160023.GA7822@mtj.duckdns.org> References: <1461597771-25352-1-git-send-email-roman.penyaev@profitbricks.com> <20160425154847.GZ7822@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160425154847.GZ7822@mtj.duckdns.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 392 Lines: 10 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! :) -- tejun