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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88BCCC3A5A0 for ; Mon, 19 Aug 2019 17:26:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 666EE22CF6 for ; Mon, 19 Aug 2019 17:26:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727690AbfHSR0i (ORCPT ); Mon, 19 Aug 2019 13:26:38 -0400 Received: from guest-port.merlins.org ([173.11.111.148]:44134 "EHLO mail1.merlins.org" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1727653AbfHSR0i (ORCPT ); Mon, 19 Aug 2019 13:26:38 -0400 Received: from merlin by mail1.merlins.org with local (Exim 4.92 #3) id 1hzlQS-0007yT-Sp by authid ; Mon, 19 Aug 2019 10:26:36 -0700 Date: Mon, 19 Aug 2019 10:26:36 -0700 From: Marc MERLIN To: Paolo Valente Cc: o1bigtenor@gmail.com, linux-block@vger.kernel.org, Linux-RAID Subject: Re: 5.1.21 Dell 2950 terrible swraid5 I/O performance with swraid on top of Perc 5/i raid0/jbod Message-ID: <20190819172636.GG5431@merlins.org> References: <20190819070823.GH12521@merlins.org> <5DCAD3D8-07B6-4A5D-A3C1-A1DF4055C5BD@linaro.org> <20190819164053.GF5431@merlins.org> <68ADE81A-2A48-4E95-91F6-60826FFDAF6F@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <68ADE81A-2A48-4E95-91F6-60826FFDAF6F@linaro.org> X-Sysadmin: BOFH X-URL: http://marc.merlins.org/ User-Agent: Mutt/1.5.13 (2006-08-11) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: marc@merlins.org Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, Aug 19, 2019 at 07:05:42PM +0200, Paolo Valente wrote: > > newmagic:~# hdparm -t /dev/md2 > > /dev/md2: > > HDIO_DRIVE_CMD(identify) failed: Inappropriate ioctl for device > > Timing buffered disk reads: 2 MB in 5.76 seconds = 355.42 kB/sec > > > > I think things hang a bit less, which I suppose it good, but the system is > > still unusable overall. > > Ok, I'm sorry it didn't help. Unless someone spots the problem > somewhere outside BFQ, I'm willing to analyze this apparently tough > scenario, as an opportunity to improve BFQ. If fine for you, just > contact me offline. I'm sure there is something very wrong somewhere, and that it's not BFQ's fault. I just haven't been able to pinpoint the problem. I ended up finding an H700 card with cables that should fit, so I'm going to try this first, and see what happens, thanks o1bigtenor for the suggestion. Linux-raid folks, the original post still has a warning likely worth looking into: [14852.341924] WARNING: CPU: 0 PID: 2530 at drivers/md/md.c:8180 md_write_inc+0x15/0x40 [md_mod] which in turn put the array in dirty mode. Best, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/