From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3FF7C32771 for ; Wed, 17 Aug 2022 18:21:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237706AbiHQSVn (ORCPT ); Wed, 17 Aug 2022 14:21:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233539AbiHQSVm (ORCPT ); Wed, 17 Aug 2022 14:21:42 -0400 X-Greylist: delayed 30524 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 17 Aug 2022 11:21:41 PDT Received: from mail.itouring.de (mail.itouring.de [85.10.202.141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74EE797D62; Wed, 17 Aug 2022 11:21:41 -0700 (PDT) Received: from tux.applied-asynchrony.com (p5ddd78be.dip0.t-ipconnect.de [93.221.120.190]) by mail.itouring.de (Postfix) with ESMTPSA id A5886103762; Wed, 17 Aug 2022 20:21:39 +0200 (CEST) Received: from [192.168.100.221] (hho.applied-asynchrony.com [192.168.100.221]) by tux.applied-asynchrony.com (Postfix) with ESMTP id 6B29EF01600; Wed, 17 Aug 2022 20:21:39 +0200 (CEST) Subject: Re: stalling IO regression since linux 5.12, through 5.18 To: Jan Kara , Chris Murphy Cc: Nikolay Borisov , Jens Axboe , Paolo Valente , Linux-RAID , linux-block , linux-kernel , Josef Bacik References: <61e5ccda-a527-4fea-9850-91095ffa91c4@www.fastmail.com> <4995baed-c561-421d-ba3e-3a75d6a738a3@www.fastmail.com> <2b8a38fa-f15f-45e8-8caa-61c5f8cd52de@www.fastmail.com> <7c830487-95a6-b008-920b-8bc4a318f10a@applied-asynchrony.com> <20220817114933.66c4g4xjsi4df2tg@quack3> <85a141ae-56a7-4dcd-b75a-04be4b276b3a@www.fastmail.com> <20220817163059.kigrvdfmxfswmhls@quack3> <51cd43f9-ab6b-4dd6-814f-e0c1ace3143c@www.fastmail.com> <20220817181554.znqljc6mmci45ukd@quack3> From: =?UTF-8?Q?Holger_Hoffst=c3=a4tte?= Organization: Applied Asynchrony, Inc. Message-ID: <902f766d-160a-f384-67d5-fa77c1d5caec@applied-asynchrony.com> Date: Wed, 17 Aug 2022 20:21:39 +0200 MIME-Version: 1.0 In-Reply-To: <20220817181554.znqljc6mmci45ukd@quack3> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2022-08-17 20:15, Jan Kara wrote: > On Wed 17-08-22 13:57:00, Chris Murphy wrote: >> On Wed, Aug 17, 2022, at 12:47 PM, Chris Murphy wrote: >> Can you boot with >>>> "megaraid_sas.host_tagset_enable = 0" kernel option and see whether the >>>> issue reproduces? >> >> This has been running an hour without symptoms. It's strongly suggestive, >> but needs to run overnight to be sure. Anecdotally, the max write IO is >> less than what I'm used to seeing. > > OK, if this indeed passes then b6e68ee82585 ("blk-mq: Improve performance > of non-mq IO schedulers with multiple HW queues") might be what's causing > issues (although I don't know how yet...). > > Honza Certainly explains why BFQ turned up as a suspect, considering it's still single-queue (fair MQ scheduling is .. complicated). -h