Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932188AbdCJEiR (ORCPT ); Thu, 9 Mar 2017 23:38:17 -0500 Received: from mail-pf0-f180.google.com ([209.85.192.180]:33724 "EHLO mail-pf0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754955AbdCJEiO (ORCPT ); Thu, 9 Mar 2017 23:38:14 -0500 Subject: Re: [PATCH v2] blk: improve order of bio handling in generic_make_request() To: NeilBrown , Jack Wang References: <87h93blz6g.fsf@notabene.neil.brown.name> <71562c2c-97f4-9a0a-32ec-30e0702ca575@profitbricks.com> <87lgsjj9w8.fsf@notabene.neil.brown.name> <87r328j00i.fsf@notabene.neil.brown.name> <87d1dphhuy.fsf@notabene.neil.brown.name> Cc: LKML , Lars Ellenberg , Kent Overstreet , Pavel Machek , Mike Snitzer , Mikulas Patocka , linux-raid@vger.kernel.org, device-mapper development , linux-block@vger.kernel.org From: Jens Axboe Message-ID: <58be6551-4aa7-72ee-1616-a1545606d029@kernel.dk> Date: Thu, 9 Mar 2017 21:38:05 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <87d1dphhuy.fsf@notabene.neil.brown.name> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 913 Lines: 23 On 03/09/2017 09:32 PM, NeilBrown wrote: > > I started looking further at the improvements we can make once > generic_make_request is fixed, and realised that I had missed an > important detail in this patch. > Several places test current->bio_list, and two actually edit the list. > With this change, that cannot see the whole lists, so it could cause a > regression. > > So I've revised the patch to make sure that the entire list of queued > bios remains visible, and change the relevant code to look at both > the new list and the old list. > > Following that there are some patches which make the rescuer thread > optional, and then starts removing it from some easy-to-fix places. Neil, note that the v2 patch is already in Linus tree as of earlier today. You need to rebase the series, and if we need fixups on top of v2, then that should be done separately and with increased urgency. -- Jens Axboe