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 B6625C48BEB for ; Wed, 14 Feb 2024 08:00:38 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SlDfSacAmvkYg4YRJ0SSR9Djg0KENVzB2R7+zG5tZ4I=; b=kAcmhJHZ3LUPoucZgDhjBKtL8h YGjFrHZg8a55Vb/Wh5xaoHJUWkSTBKEN9utD2s84pjlEONxSk4daGPRnwzKb28tAFeoAgKdkPLWoE fHOBluKmhwMugc8OP9EMN+tgaCOTJtrPHR9hu8ebpcc0pNdbuWkUN9AyvfiszkwDq04KvXgXW7d2O Ti/F13BfYBQ6lUpiqWtZec2Bx8BrSWFt7kUYBzHaTtfqg2FGoqk+6SAwMwxiUKesEa5P0M0J3g4TP 7wAm8QZJxUNB7NnuQ2dJg85mrADoELiZDVQFobnd8Iw01YJNi49fA67qMu7dhwZ6ZK/AxNEAAah69 QiPgdGrA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1raAC5-0000000C629-0scv; Wed, 14 Feb 2024 08:00:37 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1raAC1-0000000C61N-3cIn for linux-nvme@lists.infradead.org; Wed, 14 Feb 2024 08:00:35 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 0DD4C227AAD; Wed, 14 Feb 2024 09:00:25 +0100 (CET) Date: Wed, 14 Feb 2024 09:00:24 +0100 From: Christoph Hellwig To: John Garry Cc: Christoph Hellwig , axboe@kernel.dk, kbusch@kernel.org, sagi@grimberg.me, jejb@linux.ibm.com, martin.petersen@oracle.com, djwong@kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, dchinner@redhat.com, jack@suse.cz, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, jbongio@google.com, linux-scsi@vger.kernel.org, ming.lei@redhat.com, ojaswin@linux.ibm.com, bvanassche@acm.org, Alan Adamson Subject: Re: [PATCH v3 14/15] nvme: Support atomic writes Message-ID: <20240214080024.GA10357@lst.de> References: <20240124113841.31824-1-john.g.garry@oracle.com> <20240124113841.31824-15-john.g.garry@oracle.com> <20240213064204.GB23305@lst.de> <0323ba69-dff9-4465-817e-2c349141b753@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0323ba69-dff9-4465-817e-2c349141b753@oracle.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240214_000034_060831_380772DF X-CRM114-Status: GOOD ( 14.33 ) 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 On Tue, Feb 13, 2024 at 02:21:25PM +0000, John Garry wrote: >> Please also read through TP4098(a) and look at the MAM field. > > It's not public, AFAIK. Oracle is a member, so you can take a look at it easily. If we need it for Linux I can also work with the NVMe Board to release it. > And I don't think a feature which allows us to straddle boundaries is too > interesting really. Without MAM=1 NVMe can't support atomic writes larger than AWUPF/NAWUPF, which is typically set to the indirection table size. You're leaving a lot of potential unused with that.