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 E9D1CC43217 for ; Mon, 28 Nov 2022 02:26:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229652AbiK1C0n (ORCPT ); Sun, 27 Nov 2022 21:26:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbiK1C0m (ORCPT ); Sun, 27 Nov 2022 21:26:42 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91574D2C4; Sun, 27 Nov 2022 18:26:40 -0800 (PST) Received: from canpemm500004.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4NL8Pp25LBzqSgr; Mon, 28 Nov 2022 10:22:38 +0800 (CST) Received: from [10.174.179.14] (10.174.179.14) by canpemm500004.china.huawei.com (7.192.104.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Mon, 28 Nov 2022 10:26:38 +0800 Subject: Re: [PATCH RFC] scsi: core: remove unsed 'restarts' from scsi_device To: Yu Kuai , , , CC: , , , "yukuai (C)" References: <20221118113052.1324140-1-yukuai1@huaweicloud.com> From: Jason Yan Message-ID: <9a8a1930-80bf-13f1-5512-124be01fcc99@huawei.com> Date: Mon, 28 Nov 2022 10:26:37 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="gbk"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.14] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500004.china.huawei.com (7.192.104.92) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022/11/26 16:54, Yu Kuai wrote: > Hi, > > ÔÚ 2022/11/18 19:30, Yu Kuai дµÀ: >> From: Yu Kuai >> >> During code review, I found that 'restarts' is not useful anymore after >> the following commits: >> >> 1) commit ab3cee3762e5 ("blk-mq: In blk_mq_dispatch_rq_list() "no budget" >> is a reason to kick") >> 2) commit d3b38596875d ("blk-mq: run queue no matter whether the request >> is the last request") >> 3) commit 673235f91531 ("scsi: core: Fix race between handling >> STS_RESOURCE >> and completion") >> >> Now that if get budget ever failed, block layer will make sure to >> trigger new run queue for the hctx. Hence there is no need to run queue >> from scsi layer in this case. >> > > Does anyone has suggestions about this patch? > > More info why I tried to remove this: > > while testing megaraid with 4 nvme with none elevator, the default > queue_depth is 128, while I test it with fio 128 jobs and 1 iodepth, > bw is about 4Gib/s, however, if I test with 128 jobs and 2 iodepth, > bw is decreased to about 0.8Gib/s, and with this patch applied, > bw can stay 4Gib/s in the later case. > Hi Yu Kuai, This information should be included in the commit message. Thanks, Jason