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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 83FC9C76186 for ; Wed, 17 Jul 2019 07:41:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 57D0A20818 for ; Wed, 17 Jul 2019 07:41:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726141AbfGQHl0 (ORCPT ); Wed, 17 Jul 2019 03:41:26 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:38511 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725873AbfGQHl0 (ORCPT ); Wed, 17 Jul 2019 03:41:26 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id 7C61880592; Wed, 17 Jul 2019 09:41:13 +0200 (CEST) Date: Wed, 17 Jul 2019 09:41:24 +0200 From: Pavel Machek To: jglisse@redhat.com, ebaskakov@nvidia.com, jhubbard@nvidia.com, mhairgrove@nvidia.com, SCheung@nvidia.com, sgutti@nvidia.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, benh@kernel.crashing.org, dan.j.williams@intel.com, dnellans@nvidia.com, hannes@cmpxchg.org, kirill.shutemov@linux.intel.com, mhocko@kernel.org, paulmck@linux.vnet.ibm.com, ross.zwisler@linux.intel.com, vdavydov.dev@gmail.com, liubo95@huawei.com, akpm@linux-foundation.org, torvalds@linux-foundation.org, kernel list Subject: HMM_MIRROR has less than useful help text Message-ID: <20190717074124.GA21617@amd> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="EVF5PPMfhYS0aIcm" Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --EVF5PPMfhYS0aIcm Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! Commit c0b124054f9e42eb6da545a10fe9122a7d7c3f72 has very nice commit message, explaining what HMM_MIRROR is and when it is needed. Unfortunately, it did not make it into Kconfig help: CONFIG_HMM_MIRROR: Select HMM_MIRROR if you want to mirror range of the CPU page table of a process into a device page table. Here, mirror means "keep synchronized". Prerequisites: the device must provide the ability to write-protect its page tables (at PAGE_SIZE granularity), and must be able to recover =66rom the resulting potential page faults. Could that be fixed? This is key information for me: # This is a heterogeneous memory management (HMM) process address space # mirroring. # This is useful for NVidia GPU >=3D Pascal, Mellanox IB >=3D mlx5 and more # hardware in the future. Thanks, Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --EVF5PPMfhYS0aIcm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAl0u0SQACgkQMOfwapXb+vJ8zACcDY6r6pIBRTTsorfNlv1bWsri YsoAn1qx2CsKnc8psHoMGpmjiWiWW/zT =4Hji -----END PGP SIGNATURE----- --EVF5PPMfhYS0aIcm--