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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 06D31C5478C for ; Wed, 28 Feb 2024 03:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=zkoh+Wpo8OQQpFqDNxTg4P5xeSCDDGzH0oL3+AC+nNw=; b=S9B8KivpYWa4SRM3T3PGNEvuvp MMU85m0DgOWIcBgwb2Mtzhs2jEBW53pRfIX0eP9TzbajkWnU54+x87/oyOboOHjni7S8qg2+kgqws 8w0Rl8lDHNPy2359XCeWGdbiUC4eV0Ptfd3QPyAjepv7oSTVAil2gNNkHfX6ALHZ2jGE6/NQi+p9t kWoh692p6dMb+NCIFqmiV7T9qpdPi3QlgtP0sDXO7mK3+A1dPlfG7Epx/mbDCcWSbbCNlWgPJr8Xd BpSxV7xN69KKmdT3CccZwhHZpRjsYawrQtp7QIyArjYgoIx8b7/PKlN3guY4g2APKonRGsDePu0Z+ xPYdpZXw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfAoA-00000007sJX-2bix; Wed, 28 Feb 2024 03:40:38 +0000 Received: from out30-101.freemail.mail.aliyun.com ([115.124.30.101]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfAo7-00000007sIm-0EoC for linux-nvme@lists.infradead.org; Wed, 28 Feb 2024 03:40:37 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1709091631; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=zkoh+Wpo8OQQpFqDNxTg4P5xeSCDDGzH0oL3+AC+nNw=; b=njdh25btaIDk5Ima2zZM3HOTwGGCM84cNVNd9r2aLybLY1b/YYlAI0UAw4pdjCZR+LzHxp+MMFbkSfF5uhAaFZ3Po2KergCqb7d6nCWcHgSnPfBJwubJfCtSRKkYAXp0gFgRuXfM5SB9Y4g6siU67vnLjPWSJ0u00OQ/BmYSv4w= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R481e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=kanie@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0W1OQXEn_1709091627; Received: from 30.178.83.72(mailfrom:kanie@linux.alibaba.com fp:SMTPD_---0W1OQXEn_1709091627) by smtp.aliyun-inc.com; Wed, 28 Feb 2024 11:40:28 +0800 Message-ID: <727aabbc-1464-48d6-9915-a1c22343c2b2@linux.alibaba.com> Date: Wed, 28 Feb 2024 11:40:26 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 1/1] nvmet: support reservation feature Content-Language: en-GB To: Keith Busch Cc: Sagi Grimberg , hch@lst.de, kch@nvidia.com, linux-nvme@lists.infradead.org References: <20240201023207.112007-1-kanie@linux.alibaba.com> <20240201023207.112007-2-kanie@linux.alibaba.com> <0c74a2c2-c9d9-4b0c-9deb-bdc3caf72005@linux.alibaba.com> From: Guixin Liu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240227_194035_823610_9E21F886 X-CRM114-Status: GOOD ( 14.05 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org 在 2024/2/28 11:21, Keith Busch 写道: > On Wed, Feb 28, 2024 at 10:21:57AM +0800, Guixin Liu wrote: >> 在 2024/2/28 08:40, Sagi Grimberg 写道: >>> Hey Guixin, >>> >>> On 01/02/2024 4:32, Guixin Liu wrote: >>>> This patch implements the reservation feature, includes: >>>> 1. reservation register(register, unregister and replace). >>>> 2. reservation acquire(acquire, preempt, preempt and abort). >>> >>> Overall patchset looks in decent shape to me now. >>> >>> I do have one more question though. >> My thanks for your patient review. >>> You say that this patchset implements preempt and abort, however I don't >>> see how this is actually implemented or even how can it be implemented >>> at all at this point. >> Yes, the nvme target does not do any useful workto abort command, the >> comment of nvmet_execute_abort() says that >> >> "we are not required to do any useful work, and we couldn't really do a >> useful abort", >> >> so I don't know what to do about preempt and abort, and the NVMe spec says >> that the abort is best effor. >> >> My statement here may be a little inaccurate. > I think you may be mixing up the NVMe "Abort" command with a different > command, "Reservation Acquire", where RACQA is set to value 010b, > "Preempt and Abort". Sorry, I just want to explain that I dont know how to implement "preempt and abort" either.