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 B23D9C83F15 for ; Sun, 27 Aug 2023 00:46:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229515AbjH0AqK (ORCPT ); Sat, 26 Aug 2023 20:46:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229460AbjH0Ap7 (ORCPT ); Sat, 26 Aug 2023 20:45:59 -0400 Received: from mail-pf1-f180.google.com (mail-pf1-f180.google.com [209.85.210.180]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3683419A; Sat, 26 Aug 2023 17:45:57 -0700 (PDT) Received: by mail-pf1-f180.google.com with SMTP id d2e1a72fcca58-68a3082c771so1416469b3a.0; Sat, 26 Aug 2023 17:45:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693097156; x=1693701956; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=x0noXuCw4diQPVVy5tMWjuaRU2NrMA9lPR9xkJ2qTPY=; b=azA0pKXL4z+pCUgeG6MDwvEnAEn7gpMCm1RcrMk9EyVa1DSibYdGFZC5DO6/GTEkyx MykGtdgr2BtbMkUES9hSqswzybjc0miW73hRKIPuPkN4lhoVo+K0Wqe3Bbfqx0eLZPWS S9rEnIMyMNc169VA1ApWUBVFr7Z8OvPf+ptbavvkHVh723DdGlZIMYnLS5R1723QeFyt Vjl7wuulTG8DUh/OiAzy75ldlGXapJP3zfcPphkTFt3P3evzuOCok5pYY7G1onTJMJ85 lhuvkqZsG7kf3sx1h21Te1wfak105VgF/m/z00sIE2xRB8hjMUHN/YbXIwdFpYCdDBuP dFjw== X-Gm-Message-State: AOJu0YypGh7bvBbqiZBzCbY8/1jsIo/zacC3dLikm2EI858eEhQb1EYG 9swcGQCD3bX2jNo9KLjAbeI= X-Google-Smtp-Source: AGHT+IEgibIA76mDWHaRopAmphTXDvMSnqQaRh2bxRTFviWwjc2MyEgi19ys/Gu6OUOtT4Kq3DUVsQ== X-Received: by 2002:a05:6a00:a1f:b0:68a:6149:71cb with SMTP id p31-20020a056a000a1f00b0068a614971cbmr24088914pfh.5.1693097156403; Sat, 26 Aug 2023 17:45:56 -0700 (PDT) Received: from ?IPV6:2601:647:5f00:5f5:4a46:e57b:bee0:6bc6? ([2601:647:5f00:5f5:4a46:e57b:bee0:6bc6]) by smtp.gmail.com with ESMTPSA id x15-20020a056a00270f00b0068a4cd8b530sm3858797pfv.139.2023.08.26.17.45.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 26 Aug 2023 17:45:55 -0700 (PDT) Message-ID: Date: Sat, 26 Aug 2023 17:45:53 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.14.0 Subject: Re: [PATCH 0/6] blk-mq: optimize the queue_rqs() support To: Chengming Zhou , axboe@kernel.dk, hch@lst.de, ming.lei@redhat.com, kbusch@kernel.org Cc: mst@redhat.com, sagi@grimberg.me, damien.lemoal@opensource.wdc.com, kch@nvidia.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com References: <20230824144403.2135739-1-chengming.zhou@linux.dev> <84c857f7-9966-6125-92c4-1b2fa96fb98d@linux.dev> Content-Language: en-US From: Bart Van Assche In-Reply-To: <84c857f7-9966-6125-92c4-1b2fa96fb98d@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/25/23 01:24, Chengming Zhou wrote: > I don't know the details of the UFS devices bad performance problem. > But I feel it maybe caused by the too lazy queue idle handling, which > is now only handled in queue timeout work. Hi Chengming, The root cause of the UFS performance problem is the fair sharing algorithm itself: reducing the active queue count only happens after the request queue timeout has expired. This is way too slow. Last time it was proposed to remove that algorithm Yu Kuai promised to replace it by a better algorithm. Since progress on the replacement algorithm has stalled I'm asking again whether everyone agrees to remove the fairness algorithm. Thanks, Bart.