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 6C5E4C433EF for ; Fri, 11 Mar 2022 00:38:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237668AbiCKAjb (ORCPT ); Thu, 10 Mar 2022 19:39:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231950AbiCKAja (ORCPT ); Thu, 10 Mar 2022 19:39:30 -0500 Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40CCE506EB for ; Thu, 10 Mar 2022 16:38:28 -0800 (PST) Received: by mail-pg1-x52b.google.com with SMTP id o23so6069612pgk.13 for ; Thu, 10 Mar 2022 16:38:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:cc:references:in-reply-to:content-transfer-encoding; bh=7aGbdxDhXZ8wDd++KZCUu5nZoO1j5tDQvd2lHwBG6gQ=; b=QoALnnAujshwavRdNcUsNmYGnQUk0UCd7p0d3d0iTiFV810dm5E41PmYs0J6OgmSom lUSRkW60tzL4GL7b09uCb4rVbYiSBOz28eiTpA0cI+Dr23HHCdxwo+ZYqgo3k/H+G3z7 kusxKx44zrR3p2Ss6ZPID4XJSlqLatdlCVDXvl0y+gLT2HFurDSFwSDKCeZkYTacs983 jw6F4ye813rjb55/9BOTBHyj8cW4pu8bJCUvOvgJO2iaGTfMoCxSd8RoNPoE6UtEvwwT /v69q2X3wzP87G3dkWG6NlxnWrggieQwa1akAkHVcyjluoiGBTa8b5HRnKk1qzGH4zkF sLfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:cc:references:in-reply-to :content-transfer-encoding; bh=7aGbdxDhXZ8wDd++KZCUu5nZoO1j5tDQvd2lHwBG6gQ=; b=Yi0Cru7QuD6S/TBH0vVERkn9mfcrNSj/I3m/jiT79Cj9fZ1sjN+9AjVeo1UREAiJvd SMqG44YS4g2duZCf2RQCEcmJ2zZukE3Mwg/oFLXcySk6+sD5OcmL4Te18pzw40fEcwxq ncqTmFmhmJZVtHvkgMSuptbK3Bo9LCPEgMsC4bXq/jhA4h63fn2DmFDigrDMm33y4bpJ L1DCz9DS5u1nDbbxSvgtQRYVP37bRP7ZruHRPLuI8xCT972mIQuVcjTyFhNhCYQB+8NQ u5kxk9PTInkapIKWLNTu7TVulQuWinBendIEuVtTiDEnpJQ//H+oqhaWQMH0TzEiM7f5 /S9g== X-Gm-Message-State: AOAM533W/anZVbRYD518RB5U3abKC4OeznRGqq4liiaFjpVdMdBtpaU6 57kLxGF9yya6AtGYbgszpDrphQ== X-Google-Smtp-Source: ABdhPJxiGWAnrjoZu6vpBcFjJNkjglYBHZWw3rDGcDIMSYQXiuBSnmpSdBvQJ0Zr7CSoOqa5xQbCIg== X-Received: by 2002:a05:6a00:174d:b0:4f6:67e3:965 with SMTP id j13-20020a056a00174d00b004f667e30965mr7727461pfc.39.1646959107674; Thu, 10 Mar 2022 16:38:27 -0800 (PST) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id s30-20020a056a001c5e00b004f73f27aa40sm8101678pfw.161.2022.03.10.16.38.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Mar 2022 16:38:27 -0800 (PST) Message-ID: Date: Thu, 10 Mar 2022 17:38:26 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge Content-Language: en-US From: Jens Axboe To: Song Liu Cc: linux-block@vger.kernel.org, linux-raid , stable@vger.kernel.org, Larkin Lowrey , Wilson Jonathan , Roger Heflin References: <20220309064209.4169303-1-song@kernel.org> <9516f407-bb91-093b-739d-c32bda1b5d8d@kernel.dk> <38f7aaf5-2043-b4f4-1fa5-52a7c883772b@kernel.dk> <2b437948-ba2a-c59c-1059-e937ea8636bd@kernel.dk> <40ae10bd-6839-2246-c2d7-aa11e671d7d4@kernel.dk> In-Reply-To: <40ae10bd-6839-2246-c2d7-aa11e671d7d4@kernel.dk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On 3/10/22 5:36 PM, Jens Axboe wrote: > I'm assuming you have a plug setup for doing the reads, which is why you > see the big difference (or there would be none). But > blk_mq_flush_plug_list() should really take care of this when the plug > is flushed, requests should be merged at that point. And from your > description, doesn't sound like they are at all. Maybe you need a list sort in blk_mq_flush_plug_list(). If you round-robin all the drives, then we'll hit that "run queue" path for each of them when we flush. -- Jens Axboe