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,DKIMWL_WL_HIGH, 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 08190C433E0 for ; Wed, 17 Feb 2021 23:01:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBE8364E5F for ; Wed, 17 Feb 2021 23:01:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231279AbhBQXBk (ORCPT ); Wed, 17 Feb 2021 18:01:40 -0500 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:16785 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229774AbhBQXBk (ORCPT ); Wed, 17 Feb 2021 18:01:40 -0500 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Wed, 17 Feb 2021 15:00:59 -0800 Received: from nvdebian.localnet (172.20.145.6) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 17 Feb 2021 23:00:56 +0000 From: Alistair Popple To: CC: Christoph Hellwig , Jason Gunthorpe , John Hubbard , Daniel Vetter , "Nouveau Dev" , Ben Skeggs , "Andrew Morton" , Linux Doc Mailing List , Linux Kernel Mailing List , , dri-devel , Ralph Campbell , Jerome Glisse Subject: Re: [PATCH 0/9] Add support for SVM atomics in Nouveau Date: Thu, 18 Feb 2021 10:00:54 +1100 Message-ID: <6616185.Wbe1NtApLk@nvdebian> In-Reply-To: <20210211075510.GA2368090@infradead.org> References: <20210209010722.13839-1-apopple@nvidia.com> <20210210175913.GO4718@ziepe.ca> <20210211075510.GA2368090@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Originating-IP: [172.20.145.6] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1613602859; bh=Zcp6FwQOo6uCl+bAC2DWEr4Viwiu5nIBT+YN6D2qruU=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding:Content-Type: X-Originating-IP:X-ClientProxiedBy; b=AXb+ut3ot7Odaa4NfndUdnHlBWh/CmCbxa90e7XGqYDqOl0itTA0ey/0xdqSoXbA2 JlMNydOcVXGiAO1uyIryQXCh6IJNMB5+ajbf7PvbtDcER0T/TTnEqkgpU2USIY0Ya+ NqYaHlrJc7yam1VcZFkBNUvumzVGyvnQedJAd2+hs20Ac8NKfjzT6p3t31zwxNt/Hq gR+sHNOCuxdnohI6TOW7pnPo+iGVNWMyVlv0cNOIZszQSsdsXR69vsDcRIyKwiHLuU QHMPy9U3pXXKcoKf2xltHJbe92pWiS2sWG6fQJuE1wnVVzjgSmr5R0ufLguVI0LbOK oydiyGx+ixcIg== Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thursday, 11 February 2021 6:55:10 PM AEDT Christoph Hellwig wrote: > On Wed, Feb 10, 2021 at 01:59:13PM -0400, Jason Gunthorpe wrote: > > Really what you want to do here is leave the CPU page in the VMA and > > the page tables where it started and deny CPU access to the page. Then > > all the proper machinery will continue to work. > > > > IMHO "migration" is the wrong idea if the data isn't actually moving. > > Agreed. I chose "migration" because device private pages seemed like a good way of reusing existing code to do what was required (a callback on CPU access). However I have been reworking this to use mmu notifiers as the callback and it seems to simplify some things nicely so think I also agree. It removes the requirement for the pin as well which is nice, I'll post it as a v2 soon. - Alistair