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 0E4A7D3F07A for ; Wed, 28 Jan 2026 15:12:25 +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=z3GOVlCNvGMAEuEvpwco9PbQEceuiUVAGUNDmBJASB0=; b=Osw3vb6XhiLO47VtmRCoUNGhi+ EXvPQEYzgNr9gNBmy4W9+BTR1Z4Xaf0bgs2u75NYTC3UJp7pNLIvaV6PDz1CTZMMzBLzZTdWhZPcz GnDVt0BpognYfH9LitBQWxgLAabY+2BCmQY/taPFeb+sIjzICzqopALYPiYeo+ViWVTPXO4pW0QZx syx2PJcRe9GSskNciB8TgupDChDFBaNlkPMGoInmpiwofyjjs65e8qCVAYdsfhtUPMumcZy11orj2 tCx27Aouy4mggqrddyv9kmHRo0T7PXVILgVErBQiP8pKEv0tNC+uOnwzONoRCpM8UweeOvYj1Nnmi fjVEGRyQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vl7DR-0000000GFWE-2mMY; Wed, 28 Jan 2026 15:12:21 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vl7DP-0000000GFVp-3ujK for linux-nvme@lists.infradead.org; Wed, 28 Jan 2026 15:12:19 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id F31CF6000A; Wed, 28 Jan 2026 15:12:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5ED93C4CEF1; Wed, 28 Jan 2026 15:12:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769613138; bh=tN4nY6o2OcquzXHtdghuwNHaqXMTg6hLxZ+PIgKgO4U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mFwz8hIEzQlfjb+gjgppt3FKhpLu0SNuKv4NAQVejsq922pZ2BccppABFfKvX6a59 PP7VBlUoxgtRAo0x8NJ2hPhBXQpxNlffWM3Ql5d2em9AdYGvLmAmjKSb7EA+7Ih0GB m8SOSG2pHozQcVRPpwyknMFM1blxkBnDitYEo1R915dW1QkUEln3Z5IUj2ZNnHonG0 TS4ONpQwDXbgjD76HZNM+bIfTzAnU0UofPMkEwhbj71Dbb1b6sv7Sh3GJR17/I1y0+ Y+O4/usVLmQwAS1iF4UdUSDaArOwkd7/FLgmGPA1mKIlYvP5VE13DjBzjurL/G1U+a A1XsdA6Wf4ieg== Date: Wed, 28 Jan 2026 08:12:16 -0700 From: Keith Busch To: John Garry Cc: hch@lst.de, sagi@grimberg.me, axboe@fb.com, martin.petersen@oracle.com, linux-nvme@lists.infradead.org, nilay@linux.ibm.com Subject: Re: [PATCH v2] nvme: stop using AWUPF Message-ID: References: <20260128082623.3945303-1-john.g.garry@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260128082623.3945303-1-john.g.garry@oracle.com> 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 Wed, Jan 28, 2026 at 08:26:23AM +0000, John Garry wrote: > As described at [0], much of the atomic write parts of the specification > are lacking. > > For now, there is nothing which we can do in software about the lack of > a dedicated NVMe write atomic command. > > As for reading the atomic write limits, it is felt that the per-namespace > values are mostly properly specified and it is assumed that they are > properly implemented. > > The specification of NAWUPF is quite clear. However the specification of > NABSPF is less clear. The lack of clarity in NABSPF comes from deciding > whether NABSPF applies when NSABP is 0 - it is assumed that NSABPF does > not apply when NSABP is 0. > > As for the per-controller AWUPF, how this value applies to shared > namespaces is missing in the specification. Furthermore, the value is in > terms of logical blocks, which is an NS entity. > > Since AWUPF is so poorly defined, stop using it already together. > Hopefully this will force vendors to implement NAWUPF support always. > > Note that AWUPF not only effects atomic write support, but also the > physical block size reported for the device. > > To help users know this restriction, log an info message per NS. Thanks, applied to nvme-7.0.