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 6F47AC369D7 for ; Tue, 22 Apr 2025 09:52:03 +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=8+AJtABvgFwXzYTxi5z5tHd7Yx6+/IBejIizWd/FsJU=; b=sy3wQwTWwRCoGKR2Hv2IcPuOW7 S8QQcA1uS4zFRF/pANSR3lsCMw3OmgTlRf9bGhDWgYnsPk88uqkJg6M3a0jLVT2Lp/YuGSwxKN6cI yfWb1FryAqrqXTxizo0DVCsk0a0qyCvQ/x5iMH5X0hrg+9Kt0MoLpD0zTnYTGFKgikrtI7QOvXCvq Pmbgf/3hlxP7ovdyx1M7l+t6dgcjwVGJMHJuCAQR/X6GTaTFhVEY+A64xN4gnAJdVOriNvjDxdNP3 0L1l3GYzPtEWI097MruYmSf4BCmurdFFnerQTKahC16ZFzGumc0XxIqZH2+5kIwlkFQOL1QxRpRJU f18ERorg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u7AIL-00000006dFh-3xEJ; Tue, 22 Apr 2025 09:52:01 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u78oC-00000006GNN-48JV for linux-nvme@lists.infradead.org; Tue, 22 Apr 2025 08:16:50 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 7E39A68AA6; Tue, 22 Apr 2025 10:16:44 +0200 (CEST) Date: Tue, 22 Apr 2025 10:16:44 +0200 From: Christoph Hellwig To: Richard Weinberger Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, Richard Weinberger , kch@nvidia.com, sagi@grimberg.me, hch@lst.de, upstream+nvme@sigma-star.at, Damien Le Moal Subject: Re: [RFC PATCH] nvmet: Make blksize_shift configurable Message-ID: <20250422081644.GB411@lst.de> References: <20250418090834.2755289-1-richard@nod.at> <0e61c6e9-10bc-4272-b446-31e0d67547ce@kernel.org> <8418057.aG60p0z9Xu@anvil> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8418057.aG60p0z9Xu@anvil> 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-20250422_011649_166125_F0FE1EB2 X-CRM114-Status: GOOD ( 15.03 ) 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 Fri, Apr 18, 2025 at 11:56:30AM +0200, Richard Weinberger wrote: > TBH, I'm not sure whether it makes actually sense for the bdev case to make > blksize_shift configurable. > It's also worth discussing whether we should limit blksize_shift to a specific > range. Right now, any shift is accepted, and it is up to the user to > use a sane value. It should have a hard lower bound of 512 bytes (9) and for direct I/O and the bdev backend the reported dio alignment. The upper bound is capped by the nvme_lbaf field being a 8-bit value on the wire, no real need to require anything lower than that probably.