From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754515AbeDBVKw (ORCPT ); Mon, 2 Apr 2018 17:10:52 -0400 Received: from mail-yw0-f196.google.com ([209.85.161.196]:38919 "EHLO mail-yw0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753253AbeDBVKu (ORCPT ); Mon, 2 Apr 2018 17:10:50 -0400 X-Google-Smtp-Source: AIpwx4+KcJu7SZ5dBlO4jWMVeIg5k1b0nTuLw8/zXb9L98y1e925lS4GO/eEWS6yXUW1qRx6p1BnYg== Date: Mon, 2 Apr 2018 14:10:47 -0700 From: Tejun Heo To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 2/2] blk-mq: Fix request handover from timeout path to normal execution Message-ID: <20180402211047.GF388343@devbig577.frc2.facebook.com> References: <20180402190053.GC388343@devbig577.frc2.facebook.com> <20180402190120.GD388343@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, Apr 02, 2018 at 02:08:37PM -0700, Bart Van Assche wrote: > On 04/02/18 12:01, Tejun Heo wrote: > >+ * As nothing prevents from completion happening while > >+ * ->aborted_gstate is set, this may lead to ignored completions > >+ * and further spurious timeouts. > >+ */ > >+ if (rq->rq_flags & RQF_MQ_TIMEOUT_RESET) > >+ blk_mq_rq_update_aborted_gstate(rq, 0); > > Hello Tejun, > > Since this patch fixes one race but introduces another race, is this > patch really an improvement? Oh, that's not a new race. That's the same non-critical race which always existed. It's just being documented. Thanks. -- tejun