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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D004C4332F for ; Thu, 20 Jan 2022 15:27:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A7EAD6B0096; Thu, 20 Jan 2022 10:27:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A2F606B009C; Thu, 20 Jan 2022 10:27:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 91E176B009D; Thu, 20 Jan 2022 10:27:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0082.hostedemail.com [216.40.44.82]) by kanga.kvack.org (Postfix) with ESMTP id 805B86B0096 for ; Thu, 20 Jan 2022 10:27:42 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3E74594FCC for ; Thu, 20 Jan 2022 15:27:42 +0000 (UTC) X-FDA: 79051045164.07.6D7202B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf02.hostedemail.com (Postfix) with ESMTP id ED21380015 for ; Thu, 20 Jan 2022 15:27:40 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D837C61808; Thu, 20 Jan 2022 15:27:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F58CC340E0; Thu, 20 Jan 2022 15:27:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642692459; bh=Pw9woOKfBVJV94yKFOUNOSr0Qw3ODqyl0O2HtAePtz0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pOKuNzyOrqoltMx1Os0/MBtmr/0Xb8E2I3GsmntkfouHLWh2rc+3eAmcf3brDY4+t Fbmu+22jcLD8zPsoLRItEYBxaFP/LmFrM+ZNY+7Hu6v4pDwNmCdQmOBa84URMALXbP t0P5+cQEQdYOBsE97ZNpat/tAti3jxnQ18Y+zs6Ym7qyCTeHef5hOeQzXZcVJInPwz /GVflmj6mwk/B0emQh9mlNzIvE/iVZ0lh8yVxwGOrRE3cwmSIjCH0KPcw3OPiUydMC Ey4aZayhMg8op0x5rg+6sjZW9YF+bJzBfJCR6vCSv/xPMKQ/4LpvFwVvlVpa42q4+2 EQV2Hzq9pBsJA== Date: Thu, 20 Jan 2022 07:27:36 -0800 From: Keith Busch To: Christoph Hellwig Cc: Jason Gunthorpe , Matthew Wilcox , linux-kernel@vger.kernel.org, Joao Martins , John Hubbard , Logan Gunthorpe , Ming Lei , linux-block@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org, linux-rdma@vger.kernel.org, dri-devel@lists.freedesktop.org, nvdimm@lists.linux.dev Subject: Re: Phyr Starter Message-ID: <20220120152736.GB383746@dhcp-10-100-145-180.wdc.com> References: <20220111004126.GJ2328285@nvidia.com> <20220120135602.GA11223@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220120135602.GA11223@lst.de> X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: ED21380015 X-Stat-Signature: d9g96iftk1yrmi9yyguacj8fbbuqfhuz Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=pOKuNzyO; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf02.hostedemail.com: domain of kbusch@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=kbusch@kernel.org X-HE-Tag: 1642692460-163328 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jan 20, 2022 at 02:56:02PM +0100, Christoph Hellwig wrote: > - on the input side to dma mapping the bio_vecs (or phyrs) are chained > as bios or whatever the containing structure is. These already exist > and have infrastructure at least in the block layer > - on the output side I plan for two options: > > 1) we have a sane IOMMU and everyting will be coalesced into a > single dma_range. This requires setting the block layer > merge boundary to match the IOMMU page size, but that is > a very good thing to do anyway. It doesn't look like IOMMU page sizes are exported, or even necessarily consistently sized on at least one arch (power).