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=-1.0 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,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 61833C4CEC6 for ; Sun, 15 Sep 2019 03:35:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E16112077C for ; Sun, 15 Sep 2019 03:35:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E16112077C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 387466B0003; Sat, 14 Sep 2019 23:35:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3370E6B0006; Sat, 14 Sep 2019 23:35:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 24CDC6B0007; Sat, 14 Sep 2019 23:35:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id 0529B6B0003 for ; Sat, 14 Sep 2019 23:35:05 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id A2918181AC9AE for ; Sun, 15 Sep 2019 03:35:05 +0000 (UTC) X-FDA: 75935738970.02.flag40_4964aeab23937 X-HE-Tag: flag40_4964aeab23937 X-Filterd-Recvd-Size: 1522 Received: from r3-21.sinamail.sina.com.cn (r3-21.sinamail.sina.com.cn [202.108.3.21]) by imf33.hostedemail.com (Postfix) with SMTP for ; Sun, 15 Sep 2019 03:35:04 +0000 (UTC) Received: from unknown (HELO localhost.localdomain)([222.131.67.234]) by sina.com with ESMTP id 5D7DB16300012D07; Sun, 15 Sep 2019 11:35:01 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 427606629758 From: Hillf Danton To: Thomas Hellstrom Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: Re: [RFC PATCH 0/7] Emulated coherent graphics memory take 2 Date: Sun, 15 Sep 2019 11:34:50 +0800 Message-Id: <20190915033450.14008-1-hdanton@sina.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000076, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, 13 Sep 2019 11:32:06 +0200 >=20 > The mm patch page walk interface has been reworked to be similar to the > reworked page-walk code (mm/pagewalk.c). There have been two other solu= tions > to consider: > 1) Using the page-walk code. That is currently not possible since it re= quires > the mmap-sem to be held for the struct vm_area_struct vm_flags and for = huge > page splitting. The pagewalk code in this patchset can't hold the mmap = sems > since it will lead to locking inversion. Specify the locking scenario, if non-rfc is planned, to help understand the new wheel this patchset looks to create, as two days of finding it in the works after ba4e7d973dd0 failed.