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 3B06AC433EF for ; Mon, 22 Nov 2021 23:02:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231363AbhKVXFP (ORCPT ); Mon, 22 Nov 2021 18:05:15 -0500 Received: from m43-7.mailgun.net ([69.72.43.7]:55612 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229739AbhKVXFP (ORCPT ); Mon, 22 Nov 2021 18:05:15 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1637622128; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: From: References: Cc: To: Subject: MIME-Version: Date: Message-ID: Sender; bh=t0AYXy6Z6e0zzKQqgcekATfBpCZJU02TWh34xdyQLu8=; b=eYrtGbFS7Nu2QwTCz2eazd5oIa4ozliHxdslKgGhZsc/m9D21JVlVjtDv59ZSLSZk50WEvjq IJZ3mtzg9wFfxxPweS/F+3FEbpUW5VCeXiRXrHF7C0wzNfNaa1hB7HKT9F23a5qhjuHkb9KW CRSJ1F17Wq4pTb1jqHyF7Vc5iSs= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyJlNmU5NiIsICJsaW51eC1zY3NpQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n05.prod.us-east-1.postgun.com with SMTP id 619c216fe7d68470afadf8c0 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 22 Nov 2021 23:02:07 GMT Sender: asutoshd=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 7F30DC43639; Mon, 22 Nov 2021 23:02:05 +0000 (UTC) Received: from [192.168.1.3] (cpe-66-27-70-157.san.res.rr.com [66.27.70.157]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: asutoshd) by smtp.codeaurora.org (Postfix) with ESMTPSA id DE4A9C4360D; Mon, 22 Nov 2021 23:02:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 smtp.codeaurora.org DE4A9C4360D Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=codeaurora.org Message-ID: <2071f69b-885f-e0c5-3ded-9f0c39eb38ae@codeaurora.org> Date: Mon, 22 Nov 2021 15:02:02 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.1 Subject: Re: [PATCH v2 18/20] scsi: ufs: Optimize the command queueing code To: Bart Van Assche , "Martin K . Petersen" Cc: Jaegeuk Kim , Adrian Hunter , linux-scsi@vger.kernel.org, "James E.J. Bottomley" , Bean Huo , Can Guo , Avri Altman , Stanley Chu , Keoseong Park References: <20211119195743.2817-1-bvanassche@acm.org> <20211119195743.2817-19-bvanassche@acm.org> From: "Asutosh Das (asd)" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 11/22/2021 10:13 AM, Bart Van Assche wrote: > On 11/22/21 9:46 AM, Asutosh Das (asd) wrote: >> On 11/19/2021 11:57 AM, Bart Van Assche wrote: >>> +    blk_freeze_queue_start(hba->tmf_queue); >>> +    blk_freeze_queue_start(hba->cmd_queue); >>> +    shost_for_each_device(sdev, hba->host) >>> +        blk_freeze_queue_start(sdev->request_queue); >> >> This would still issue the requests present in the queue before >> freezing and that's a concern. > > Isn't that exactly what the existing code is doing since the existing > code waits until both doorbell registers are zero? See also > ufshcd_wait_for_doorbell_clr(). > > Thanks, > > Bart. Current code waits for the already issued requests to complete. It doesn't issue the yet-to-be issued requests. Wouldn't freezing the queue issue the requests in the context of scaling_{up/down}? If yes, I don't think the current code is doing that. -asd -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, Linux Foundation Collaborative Project