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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33218C433DB for ; Tue, 26 Jan 2021 18:17:54 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E72FA20780 for ; Tue, 26 Jan 2021 18:17:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E72FA20780 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kioxia.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CEciRsWTQgREFTW7TyrKEaaKkLiYT8Pa+7XgbdR61zE=; b=RkuZrGepZhkZ681LxtOsXHJLq xew5hVpEK5INoxoK3xyjic8KlF7jl5qmwW8A2MCnaGI23Y5c8/p4fCUbVSiHuet73tTIcwhQXxc5U wzBNWn1VAZ467UZ+iY6UMK0zYnOFx5UQzMJ/+DZc4bscdSisK9Q/efVk8iDODdrrVndZItsmyOVRV ibcGRiXGT+RUfPtMU2sk77vTTKptLofB7UKHkhU0NkCJ97yamaDVATmpO8ExDj5c6VcU+GvJW9S9F IEfpM6pzBd5XauVlGnW34WCOnUie4FCctKF81PnpBR7AgtVHz8+TLeEO5syrdcxZBcvzXTbSLXYnu 9uOOVI0wA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4Stv-0006nZ-Lc; Tue, 26 Jan 2021 18:17:15 +0000 Received: from usmailhost21.kioxia.com ([12.0.68.226] helo=SJSMAIL01.us.kioxia.com) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4Stq-0006mY-2E for linux-nvme@lists.infradead.org; Tue, 26 Jan 2021 18:17:13 +0000 Received: from SJSMAIL01.us.kioxia.com (10.90.133.90) by SJSMAIL01.us.kioxia.com (10.90.133.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Tue, 26 Jan 2021 10:17:06 -0800 Received: from SJSMAIL01.us.kioxia.com ([fe80::98fb:6d15:be65:b22d]) by SJSMAIL01.us.kioxia.com ([fe80::98fb:6d15:be65:b22d%3]) with mapi id 15.01.1779.007; Tue, 26 Jan 2021 10:17:06 -0800 From: Clay Mayers To: Chaitanya Kulkarni , "linux-nvme@lists.infradead.org" Subject: RE: [PATCH V2 0/2] nvme: Support for fused NVME_IOCTL_SUBMIT_IO Thread-Topic: [PATCH V2 0/2] nvme: Support for fused NVME_IOCTL_SUBMIT_IO Thread-Index: AQHW81Uk6e6cbZGyEU2+tznAk87Vf6o6HfbQ Date: Tue, 26 Jan 2021 18:17:06 +0000 Message-ID: References: <20210105224939.1336-2-clay.mayers@kioxia.com> <20210125195844.1390581-1-clay.mayers@kioxia.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.93.57.231] MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210126_131710_142023_4F396FB0 X-CRM114-Status: GOOD ( 10.46 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , Jens Axboe , Christoph Hellwig , Sagi Grimberg Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org > From: Chaitanya Kulkarni > Sent: Monday, January 25, 2021 5:43 PM > To: Clay Mayers ; linux-nvme@lists.infradead.org > Cc: Keith Busch ; Jens Axboe ; > Christoph Hellwig ; Sagi Grimberg > Subject: Re: [PATCH V2 0/2] nvme: Support for fused > NVME_IOCTL_SUBMIT_IO > > On 1/25/21 12:03, clay.mayers@kioxia.com wrote: > > Local pci device fused support is also necessary for NVMeOF targets to > > support fused operation. > Please explain the use case and the application of the NVMeOF fuse > command feature. NVMeOF devices are used to create disaggregated storage systems where compute and storage are connected over a fabric. Fused compare/write can be used to arbitrate shared access to NVMeOF devices w/o a central authority. A specific example of how fused compare/write is used is the clustered file system VMFS. It uses the SCSI version of compare/write to manage meta data on shared SAN systems. File system meta data is updated using locks stored on the storage media. Those locks are grabbed using fused compare/write operations as an atomic test & set. VMFS originally used device reserve, which is a courser gained locking mechanism but it doesn't scale as well as an atomic test & set. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme