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 A964AC433F5 for ; Mon, 21 Mar 2022 16:21:44 +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=DixqukwzuS2LIzDuWHjwAsxz7jLNGz0GtACZ41hJOyo=; b=BZmakSxbbvbccnPzvpOl2R6qpD 7OMwCQy0yutRLb5C2moHPQhu40aIAF9tLWFVi7VAw7u6WuhZrqbVsvYqKHc8NNP6yKgzx37CgFjBR vC14NcWIOFKN7GoYkYJssMiAw/vX1DE/xNGIsa2Mv07NCL9pSosYmSS/eGW1nlZ4lUPIKsSbie8Kl LFBWOCTE56Gkv8juQA4AnUxZr7COD6DPsqTGI7Y7yFg0cr7/PfFJVXqnAXZfwgXyOZO3XN1hLX5PW mHnV5gu6RsXNMJO2o4ekzYUvbgis8lEfENyHIWllWudFGrbdoKYbS1ecb0d08+MG0pj7SvdmxUiKB DsFr3TsQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nWKmn-008N9R-M9; Mon, 21 Mar 2022 16:21:37 +0000 Received: from out2.migadu.com ([2001:41d0:2:aacc::]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nWKmk-008N8u-CR for linux-nvme@lists.infradead.org; Mon, 21 Mar 2022 16:21:36 +0000 Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1647879688; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DixqukwzuS2LIzDuWHjwAsxz7jLNGz0GtACZ41hJOyo=; b=nqhpik62lwaJupQ2i0fizF35jRpWCnW828uBzWnTA/uKigz/781a7sTOcekSioEKjVRHS5 hab4EMW08OHHdz5/NAje1/GW2MN3YBCgbDUWODzzTToOtTFfT2IFfpiAUngDb+6lDNrgju hXh3k6ehayg7ub1ieEXBl+7rAWxdlMw= Date: Mon, 21 Mar 2022 10:21:36 -0600 MIME-Version: 1.0 Subject: Re: [PATCH 0/6] power_of_2 emulation support for NVMe ZNS devices Content-Language: en-US To: Keith Busch , Luis Chamberlain Cc: Christoph Hellwig , Pankaj Raghav , Adam Manzanares , =?UTF-8?Q?Javier_Gonz=c3=a1lez?= , jiangbo.365@bytedance.com, kanchan Joshi , Jens Axboe , Sagi Grimberg , =?UTF-8?Q?Matias_Bj=c3=b8rling?= , Pankaj Raghav , Kanchan Joshi , linux-block@vger.kernel.org, linux-nvme@lists.infradead.org, Damien Le Moal References: <20220308165349.231320-1-p.raghav@samsung.com> <20220310094725.GA28499@lst.de> <20220310144449.GA1695@lst.de> <20220311205135.GA413653@dhcp-10-100-145-180.wdc.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Jonathan Derrick In-Reply-To: <20220311205135.GA413653@dhcp-10-100-145-180.wdc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220321_092134_770493_9C55838A X-CRM114-Status: GOOD ( 13.33 ) 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 3/11/2022 1:51 PM, Keith Busch wrote: > On Fri, Mar 11, 2022 at 12:19:38PM -0800, Luis Chamberlain wrote: >> NAND has no PO2 requirement. The emulation effort was only done to help >> add support for !PO2 devices because there is no alternative. If we >> however are ready instead to go down the avenue of removing those >> restrictions well let's go there then instead. If that's not even >> something we are willing to consider I'd really like folks who stand >> behind the PO2 requirement to stick their necks out and clearly say that >> their hw/fw teams are happy to deal with this requirement forever on ZNS. > > Regardless of the merits of the current OS requirement, it's a trivial > matter for firmware to round up their reported zone size to the next > power of 2. This does not create a significant burden on their part, as > far as I know. Sure wonder why !PO2 keeps coming up if it's so trivial to fix in firmware as you claim. I actually find the hubris of the Linux community wrt the whole PO2 requirement pretty exhausting. Consider that some SSD manufacturers are having to rely on a NAND shortage and existing ASIC architecture limitations that may define the sizes of their erase blocks and write units. A !PO2 implementation in the Linux kernel would enable consumers to be able to choose more options in the marketplace for their Linux ZNS application.