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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6B97C07E9A for ; Wed, 14 Jul 2021 15:04:30 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5505A613C5 for ; Wed, 14 Jul 2021 15:04:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5505A613C5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 0060683CBB; Wed, 14 Jul 2021 15:04:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qkTps4LTewbu; Wed, 14 Jul 2021 15:04:29 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp1.osuosl.org (Postfix) with ESMTPS id EDCBB83CA3; Wed, 14 Jul 2021 15:04:28 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 94B6AC001A; Wed, 14 Jul 2021 15:04:28 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id B12E4C000E for ; Wed, 14 Jul 2021 14:24:36 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 92CCE83BFB for ; Wed, 14 Jul 2021 14:24:36 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pgaSQ9rQjEPg for ; Wed, 14 Jul 2021 14:24:36 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.osuosl.org (Postfix) with ESMTPS id 1DB6383BF8 for ; Wed, 14 Jul 2021 14:24:36 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 57CFD61154; Wed, 14 Jul 2021 14:24:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626272675; bh=uGr4g/Ee6pV+EYvldgWLzrmg2C688Tc8vlJSlq63pk8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=cET9p+pZsUlfkwOTPAtB5/mDe7yDJsg4FzfZffrQRnOVuD0rYqFVb6ZeVscmNktjM bNA7IV3qJNt14ok7rAS5FJ3LfAXGNCKyl42bXGsyuyHfNyQIkBZURhjTYhGVDqTBSH TxgYKIosOSty1JV9snDp7ZdJ2NYRoq/gkKi0nMNIZMI7NA/frs3I90G5cVnZT1Cid6 WIvbWsHG0zjCrPhEFXqGGcASjc9YI16y+p/Xh8ELeyNyhOoZo7e9/786yUHZUa6oAg Do/lYC41xrtfNZS757OeycCgPNWOg2pYEI3fjwaTGVfKxUaSRe6HSlXOboC0wLIOdF XC0EsUYXlRjdg== Subject: Re: [PATCH v7 00/15] Optimizing iommu_[map/unmap] performance To: Georgi Djakov , will@kernel.org, robin.murphy@arm.com References: <1623850736-389584-1-git-send-email-quic_c_gdjako@quicinc.com> From: Georgi Djakov Message-ID: Date: Wed, 14 Jul 2021 17:24:29 +0300 MIME-Version: 1.0 In-Reply-To: <1623850736-389584-1-git-send-email-quic_c_gdjako@quicinc.com> Content-Language: en-US X-Mailman-Approved-At: Wed, 14 Jul 2021 15:04:27 +0000 Cc: isaacm@codeaurora.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, pratikp@codeaurora.org, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On 16.06.21 16:38, Georgi Djakov wrote: > When unmapping a buffer from an IOMMU domain, the IOMMU framework unmaps > the buffer at a granule of the largest page size that is supported by > the IOMMU hardware and fits within the buffer. For every block that > is unmapped, the IOMMU framework will call into the IOMMU driver, and > then the io-pgtable framework to walk the page tables to find the entry > that corresponds to the IOVA, and then unmaps the entry. > > This can be suboptimal in scenarios where a buffer or a piece of a > buffer can be split into several contiguous page blocks of the same size. > For example, consider an IOMMU that supports 4 KB page blocks, 2 MB page > blocks, and 1 GB page blocks, and a buffer that is 4 MB in size is being > unmapped at IOVA 0. The current call-flow will result in 4 indirect calls, > and 2 page table walks, to unmap 2 entries that are next to each other in > the page-tables, when both entries could have been unmapped in one shot > by clearing both page table entries in the same call. > > The same optimization is applicable to mapping buffers as well, so > these patches implement a set of callbacks called unmap_pages and > map_pages to the io-pgtable code and IOMMU drivers which unmaps or maps > an IOVA range that consists of a number of pages of the same > page size that is supported by the IOMMU hardware, and allows for > manipulating multiple page table entries in the same set of indirect > calls. The reason for introducing these callbacks is to give other IOMMU > drivers/io-pgtable formats time to change to using the new callbacks, so > that the transition to using this approach can be done piecemeal. Hi Will, Did you get a chance to look at this patchset? Most patches are already acked/reviewed and all still applies clean on rc1. Thanks, Georgi _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu