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 24D5AC43334 for ; Tue, 14 Jun 2022 18:20:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345283AbiFNSUh (ORCPT ); Tue, 14 Jun 2022 14:20:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238046AbiFNSUg (ORCPT ); Tue, 14 Jun 2022 14:20:36 -0400 Received: from mail-pj1-f41.google.com (mail-pj1-f41.google.com [209.85.216.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5357D46B08; Tue, 14 Jun 2022 11:20:36 -0700 (PDT) Received: by mail-pj1-f41.google.com with SMTP id gc3-20020a17090b310300b001e33092c737so9813579pjb.3; Tue, 14 Jun 2022 11:20:36 -0700 (PDT) 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:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=/w8Hp9XqpCFglm0lyCJJnMaxnR+g0jbmO4+b2w/JSEA=; b=aUR6+LbwguqtVd8CspF8pjqvN00xuMeteRsLjJ/UuEGLK4TyGbN10O8UQvFy+hh1fI ImL1yV2DOsCnthQEQll1d9ATLnvcaHtBn4JALUnI4egjh417gghgjPiv2fO77IfBvzyn SlxhSdyNSrecpvnSMni+eYznHcaxP6zJcWML57yzRN178cEmp1OaH4pFZ49TU96jySy2 qXgDDH0RrhH66Mm/apZj8rHb1StxrvgsGEgrv8PmyH/3r0pS4WsJf+MAQmSsuk6Bbcsi k5U5cVd0LF4SKDqibuBs0gROdkGkmnx2hzkJJBhl8VlGval9h3N3ZyriSynJLk4SyikV aXDg== X-Gm-Message-State: AJIora82nNrdZPZYESCNIMlUzSbjp+b/0lDZPaQ5XPVeOYX0dmMDCEsC kb04E1FDlFCTadXflZisGkk= X-Google-Smtp-Source: AGRyM1uJtzcJD6jkzWIeq/vhd/KNLcj/xUnXcUTKXqqen7ST4pnXiahyp/FN/iEDVttrDcmSasNgPQ== X-Received: by 2002:a17:902:c40d:b0:164:1a71:f7c0 with SMTP id k13-20020a170902c40d00b001641a71f7c0mr5453260plk.90.1655230835619; Tue, 14 Jun 2022 11:20:35 -0700 (PDT) Received: from ?IPV6:2620:15c:211:201:ab60:e1ea:e2eb:c1b6? ([2620:15c:211:201:ab60:e1ea:e2eb:c1b6]) by smtp.gmail.com with ESMTPSA id c25-20020a637259000000b00408b01faf87sm1439646pgn.67.2022.06.14.11.20.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 14 Jun 2022 11:20:34 -0700 (PDT) Message-ID: <9e89360d-3325-92af-0436-b34df748f3e2@acm.org> Date: Tue, 14 Jun 2022 11:20:32 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH RFC v2 03/18] scsi: core: Implement reserved command handling Content-Language: en-US To: Damien Le Moal , John Garry , axboe@kernel.dk, jejb@linux.ibm.com, martin.petersen@oracle.com, brking@us.ibm.com, hare@suse.de, hch@lst.de Cc: linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, chenxiang66@hisilicon.com References: <1654770559-101375-1-git-send-email-john.garry@huawei.com> <1654770559-101375-4-git-send-email-john.garry@huawei.com> From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 6/13/22 00:01, Damien Le Moal wrote: > On 6/9/22 19:29, John Garry wrote: >> + /* >> + * This determines how many commands the HBA will set aside >> + * for internal commands. This number will be added to >> + * @can_queue to calcumate the maximum number of simultaneous > > s/calcumate/calculate > > But this is weird. For SATA, can_queue is 32. Having reserved commands, > that number needs to stay the same. We cannot have more than 32 tags. > I think keeping can_queue as the max queue depth with at most > nr_reserved_cmds tags reserved is better. > >> + * commands sent to the host. >> + */ >> + int nr_reserved_cmds; +1 for Damien's request. I also prefer to keep can_queue as the maximum queue depth, whether or not nr_reserved_cmds has been set. Thanks, Bart.