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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 ABC83C433DB for ; Mon, 1 Mar 2021 08:44:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 615F764E45 for ; Mon, 1 Mar 2021 08:44:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 615F764E45 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EEE648D0059; Mon, 1 Mar 2021 03:44:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E9E098D0019; Mon, 1 Mar 2021 03:44:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DB3FF8D0059; Mon, 1 Mar 2021 03:44:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0218.hostedemail.com [216.40.44.218]) by kanga.kvack.org (Postfix) with ESMTP id C63A68D0019 for ; Mon, 1 Mar 2021 03:44:18 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 9899468BE for ; Mon, 1 Mar 2021 08:44:18 +0000 (UTC) X-FDA: 77870668596.23.2E06732 Received: from mail-wm1-f44.google.com (mail-wm1-f44.google.com [209.85.128.44]) by imf16.hostedemail.com (Postfix) with ESMTP id 5716680192D8 for ; Mon, 1 Mar 2021 08:44:17 +0000 (UTC) Received: by mail-wm1-f44.google.com with SMTP id o7-20020a05600c4fc7b029010a0247d5f0so2568020wmq.1 for ; Mon, 01 Mar 2021 00:44:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:in-reply-to; bh=casXV986YYPpP/xVweHLp0D+mMI8e5v7nph9gP3C210=; b=KwubmRjBCacpJEoQ8nI/i0O6N0bT0UF+rjnwIHXkRjuHaOxDxcAX0+0VI97PkXE4F8 p7b3CKJDuNdeBcyWyvkGT1jJBXYzz0SpeF3EyRCUj7ZrYmituxGo0H3ApF/wvLI4V94g 6t027mMCenAmki/gYvyzyzx95eC0WzyShZCyI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :in-reply-to; bh=casXV986YYPpP/xVweHLp0D+mMI8e5v7nph9gP3C210=; b=N2wFNkKt5nXojiBULFf5D4lgyc5GBEFiVbxS3O6zqjtzxQQsX5ArsRA5R+2CcaOmy/ b5wnEWCL2IOs8H4UfmTWAgj2U+NC0jMknkE1JrLeH4HEIUOVhR44HJMEb/xNboqwTsxM M+iNZv7RXc2bs2iFDL8V5NLK+ZTRLS0vw1g9rqEjCLPc+Mo0/fG2bPxMFdOy7VtUqQd4 pE9NxfQWVGAWzWSF7XIHxAEScm1UKd432D9QcHM+fBFXIVYQWcKdwffMv8i+zfzrjilz mLxk3gk8TxFOgnH531lhrXQfsw/5WYUZv0mC3tO8mrKR0f5TQvG9q8O75Em7bppVW8hs jh+A== X-Gm-Message-State: AOAM532546+cYQWtI2jwOmj6u4U5s2zG5rmVgvGVZp6MQEAU/jan0MQq ufl3hC9O9TXcJHZ8Vc/6kft4hw== X-Google-Smtp-Source: ABdhPJw127V6ng7xDem45/zMMy84q21yO4BFfknDh2GJ/IHtBlg9Nbdd5BlIUoB8hUto+ypMIgI5XA== X-Received: by 2002:a05:600c:2248:: with SMTP id a8mr14413003wmm.167.1614588256291; Mon, 01 Mar 2021 00:44:16 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id l22sm25045665wrb.4.2021.03.01.00.44.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Mar 2021 00:44:15 -0800 (PST) Date: Mon, 1 Mar 2021 09:44:13 +0100 From: Daniel Vetter To: Christoph Hellwig Cc: Andrew Morton , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Chris Wilson , Daniel Vetter , Peter Zijlstra , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: add remap_pfn_range_notrack instead of reinventing it in i915 Message-ID: Mail-Followup-To: Christoph Hellwig , Andrew Morton , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Chris Wilson , Peter Zijlstra , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org References: <20210301083320.943079-1-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210301083320.943079-1-hch@lst.de> X-Operating-System: Linux phenom 5.7.0-1-amd64 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 5716680192D8 X-Stat-Signature: nzn5mn4qsyzmgsq98sbtmnuqraabod5m Received-SPF: none (ffwll.ch>: No applicable sender policy available) receiver=imf16; identity=mailfrom; envelope-from=""; helo=mail-wm1-f44.google.com; client-ip=209.85.128.44 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1614588257-651446 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 Mon, Mar 01, 2021 at 09:33:18AM +0100, Christoph Hellwig wrote: > Hi all, > > i915 has some reason to want to avoid the track_pfn_remap overhead in > remap_pfn_range. Add a function to the core VM to do just that rather > than reinventing the functionality poorly in the driver. It's not _notrack it's "rely on the tracking established by the struct io_mapping". Exporting a _notrack version to drivers sounds like not something we want to ever do. So I think you want a helper which takes the io_mapping, and not something that encourages drivers to go full stupid. > Note that the remap_io_sg path does get exercises when using Xorg on my > Thinkpad X1, so this should be considered lightly tested, I've not > managed to hit the remap_io_mapping path at all. Needs an older machine and old userspace. intel-gfx CI should still check whether it's all ok. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch