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 3C082C77B73 for ; Tue, 30 May 2023 23:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233830AbjE3Xu6 (ORCPT ); Tue, 30 May 2023 19:50:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229590AbjE3Xu4 (ORCPT ); Tue, 30 May 2023 19:50:56 -0400 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF8F1B2; Tue, 30 May 2023 16:50:55 -0700 (PDT) Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-1b01dac1a82so28840415ad.2; Tue, 30 May 2023 16:50:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685490655; x=1688082655; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=i06h5BK+XtAu5jXCBUd3D2Pr9DE1D8oH6P1s8vIA0QM=; b=k20A6MygE0PsVMh/vnP3VhufVUN/vnRUEeJ0xkDCdij7HvhSWINjlPmdUKOnXMcukQ qr/HWjznLS7+0/gP5NUem5s6PPS/auHTOWezxyzCXaeikTOtczwqyevUd2LzjYfzK3Wb a2xfR9a8KFr/w/yLdRh9BGIRYTxDGHrehHW9iwClAVHHgv0BC4c+Ktzb0dDF1ei7N0p6 ugtU7pQQehyDGrtUvEZVIsm5cXSb+eKF5JgNxFZ0zSi0Ltf9lpd0FV7JtEmUl27KBdlh sf+pymjjfsGT7Ho0UTq4txdy4mieUZk7ENTjXqvWx4+F6Zmq6mXyiSGAvFLZ4iu9dAqH nRxg== X-Gm-Message-State: AC+VfDwdFekYoWgRTtIxCs3pjj2ZIOZ2EVGCV5G/QWjv/0CiPhVljwaO Lnb+j2UATbQrxGW6bvceGPY= X-Google-Smtp-Source: ACHHUZ5q2rHhMeGb6KiH+LiODYM8ZJD5Z/27qCZSHx6XU038OIaBVsCApVD+YW5jC3EWzB+l3X8JCA== X-Received: by 2002:a17:902:c40f:b0:1b0:286f:233a with SMTP id k15-20020a170902c40f00b001b0286f233amr3875945plk.61.1685490655006; Tue, 30 May 2023 16:50:55 -0700 (PDT) Received: from [192.168.51.14] ([98.51.102.78]) by smtp.gmail.com with ESMTPSA id u14-20020a170902e80e00b001aae909cfbbsm10839276plg.119.2023.05.30.16.50.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 May 2023 16:50:54 -0700 (PDT) Message-ID: Date: Tue, 30 May 2023 16:50:53 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v2 1/1] scsi: ufs: core: Make UFS_MCQ_NUM_DEV_CMD_QUEUES a module parameter Content-Language: en-US To: Po-Wen Kao , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Alim Akhtar , Avri Altman , "James E.J. Bottomley" , "Martin K. Petersen" , Matthias Brugger , AngeloGioacchino Del Regno Cc: wsd_upstream@mediatek.com, peter.wang@mediatek.com, stanley.chu@mediatek.com, alice.chao@mediatek.com, naomi.chu@mediatek.com, chun-hung.wu@mediatek.com, cc.chou@mediatek.com, eddie.huang@mediatek.com References: <20230530023518.16965-1-powen.kao@mediatek.com> From: Bart Van Assche In-Reply-To: <20230530023518.16965-1-powen.kao@mediatek.com> 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 5/29/23 19:35, Po-Wen Kao wrote: > A dedicated queue for dev commands is not mandatory, hence let > UFS_MCQ_NUM_DEV_CMD_QUEUES become module parameter `dev_cmd_queues` > to allow sharing first hw queue for dev commands. > > When `dev_cmd_queues` is set to 0, the hwq 0 will be shared for I/O > requests and dev commands. In the same hwq, commands are processed based > on submission order hence might take longer to dispatch dev command > under heavy traffic. For the host with dedicated hwq for dev commands > can benefit in such scenario. The UFS core has already too many kernel module parameters. I don't think that we need more kernel module parameters. Instead of adding a new kernel module parameter, I propose to never reserve a hardware queue for device commands. Reserving a hardware queue for device commands seems wasteful to me. Thanks, Bart.