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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 4F1E0C43441 for ; Mon, 12 Nov 2018 19:36:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0FDD2224E0 for ; Mon, 12 Nov 2018 19:36:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0FDD2224E0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726391AbeKMFap (ORCPT ); Tue, 13 Nov 2018 00:30:45 -0500 Received: from mx2.suse.de ([195.135.220.15]:58968 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725790AbeKMFap (ORCPT ); Tue, 13 Nov 2018 00:30:45 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 641F2AE4F; Mon, 12 Nov 2018 19:36:04 +0000 (UTC) To: Jean Delvare , David Airlie Cc: christian.koenig@amd.com, dri-devel , linux-kernel , Takashi Iwai References: <20181101162707.598c1718@endymion> <20181108130509.3b2d42ff@endymion> <1542033367.2661.33.camel@suse.de> From: Thomas Zimmermann Openpgp: preference=signencrypt Autocrypt: addr=tzimmermann@suse.de; keydata= xsBNBFs50uABCADEHPidWt974CaxBVbrIBwqcq/WURinJ3+2WlIrKWspiP83vfZKaXhFYsdg XH47fDVbPPj+d6tQrw5lPQCyqjwrCPYnq3WlIBnGPJ4/jreTL6V+qfKRDlGLWFjZcsrPJGE0 BeB5BbqP5erN1qylK9i3gPoQjXGhpBpQYwRrEyQyjuvk+Ev0K1Jc5tVDeJAuau3TGNgah4Yc hdHm3bkPjz9EErV85RwvImQ1dptvx6s7xzwXTgGAsaYZsL8WCwDaTuqFa1d1jjlaxg6+tZsB 9GluwvIhSezPgnEmimZDkGnZRRSFiGP8yjqTjjWuf0bSj5rUnTGiyLyRZRNGcXmu6hjlABEB AAHNKFRob21hcyBaaW1tZXJtYW5uIDx0emltbWVybWFubkBzdXNlLmNvbT7CwJQEEwEIAD4W IQRyF/usjOnPY0ShaOVoDcEdUwt6IwUCWznTtgIbAwUJA8JnAAULCQgHAgYVCgkICwIEFgID AQIeAQIXgAAKCRBoDcEdUwt6I7D7CACBK42XW+7mCiK8ioXMEy1NzGbXC51RzGea8N83oEJS 1KVUtQxrkDxgrW/WLSl/TfqHFsJpdEFOv1XubWbleun3uKPy0e5vZCd5UjZPkeNjnqfCYTDy hVVsdOuFbtWDppJyJrThLqr9AgSFmoCNNUt1SVpYEEOLNE6C32BhlnSq21VLC+YXTgO/ZHTa YXkq54hHj63jwrcjkBSCkXLh37kHeqnl++GHpN+3R+o3w2OpwHAlvVjdKPT27v1tVkiydsFG 65Vd0n3m/ft+IOrGgxQM1C20uqKvsZGB4r3OGR50ekAybO7sjEJJ1Obl4ge/6RRqcvKz4LMb tGs85D6tPIeFzsBNBFs50uABCADGJj+DP1fk+UWOWrf4O61HTbC4Vr9QD2K4fUUHnzg2B6zU R1BPXqLGG0+lzK8kfYU/F5RjmEcClsIkAaFkg4kzKP14tvY1J5+AV3yNqcdg018HNtiyrSwI E0Yz/qm1Ot2NMZ0DdvVBg22IMsiudQ1tx9CH9mtyTbIXgACvl3PW2o9CxiHPE/bohFhwZwh/ kXYYAE51lhinQ3oFEeQZA3w4OTvxSEspiQR8dg8qJJb+YOAc5IKk6sJmmM7JfFMWSr22satM 23oQ3WvJb4RV6HTRTAIEyyZS7g2DhiytgMG60t0qdABG5KXSQW+OKlZRpuWwKWaLh3if/p/u 69dvpanbABEBAAHCwHwEGAEIACYWIQRyF/usjOnPY0ShaOVoDcEdUwt6IwUCWznS4AIbDAUJ A8JnAAAKCRBoDcEdUwt6I6X3CACJ8D+TpXBCqJE5xwog08+Dp8uBpx0T9n1wE0GQisZruACW NofYn8PTX9k4wmegDLwt7YQDdKxQ4+eTfZeLNQqWg6OCftH5Kx7sjWnJ09tOgniVdROzWJ7c VJ/i0okazncsJ+nq48UYvRGE1Swh3A4QRIyphWX4OADOBmTFl9ZYNPnh23eaC9WrNvFr7yP7 iGjMlfEW8l6Lda//EC5VpXVNza0xeae0zFNst2R9pn+bLkihwDLWxOIyifGRxTqNxoS4I1aw VhxPSVztPMSpIA/sOr/N/p6JrBLn+gui2K6mP7bGb8hF+szfArYqz3T1rv1VzUWAJf5Wre5U iNx9uqqx Subject: Re: Performance regression in ast drm driver Message-ID: Date: Mon, 12 Nov 2018 20:36:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.0 MIME-Version: 1.0 In-Reply-To: <1542033367.2661.33.camel@suse.de> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="qe8FfTZQBr9r2XWiH4uNUyamIlp6fkMZq" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --qe8FfTZQBr9r2XWiH4uNUyamIlp6fkMZq Content-Type: multipart/mixed; boundary="Rn4ndp8dEZpMy3RT5hxOPCcvAIMetoyR9"; protected-headers="v1" From: Thomas Zimmermann To: Jean Delvare , David Airlie Cc: christian.koenig@amd.com, dri-devel , linux-kernel , Takashi Iwai Message-ID: Subject: Re: Performance regression in ast drm driver References: <20181101162707.598c1718@endymion> <20181108130509.3b2d42ff@endymion> <1542033367.2661.33.camel@suse.de> In-Reply-To: <1542033367.2661.33.camel@suse.de> --Rn4ndp8dEZpMy3RT5hxOPCcvAIMetoyR9 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Jean Am 12.11.18 um 15:36 schrieb Jean Delvare: > Hi David, >=20 > On Fri, 2018-11-09 at 10:04 +1000, David Airlie wrote: >> On Thu, Nov 8, 2018 at 10:05 PM Jean Delvare wrote:= >>> >>> On Thu, 1 Nov 2018 16:27:07 +0100, Jean Delvare wrote: >>>> Hi David, >>>> >>>> The following commit: >>>> >>>> commit 7cf321d118a825c1541b43ca45294126fd474efa >>>> Author: Dave Airlie >>>> Date: Mon Oct 24 15:37:48 2016 +1000 >>>> >>>> drm/drivers: add support for using the arch wc mapping API. >>>> >>>> is causing a huge performance regression for the ast drm driver. In = a >>>> text console, if I call "cat" on a large text file, it takes almost >>>> twice as much time to be displayed and scrolled completely. >>>> >>>> Can you please check that the ast driver portion of that commit is b= oth >>>> correct and complete? >>> >>> And in the meantime, what bad will happen if we just revert the ast >>> portion of that commit? >> >> This seems likely to be a hw problem with PCI writes to the AST "GPU",= >> since it's just some sort of RAM + ARM on the end of a PCIE bus, we've= >> definitely seen possible issues in the past with write combining >> around some of the mga GPUs with some CPUs. >=20 > Takashi asked me to compare the contents of > /sys/kernel/debug/x86/pat_memtype_list before and after the commit > above. Before the commit, we have: >=20 > uncached-minus @ 0xfafe0000-0xfb000000 > uncached-minus @ 0xfb000000-0xfb005000 > write-combining @ 0xfb005000-0xfb584000 >=20 > After the commit, we have: >=20 > uncached-minus @ 0xfafe0000-0xfb000000 > uncached-minus @ 0xfb000000-0xfb005000 > uncached-minus @ 0xfb000000-0xfb800000 > uncached-minus @ 0xfb005000-0xfb584000 >=20 > The corresponding lines in /proc/iomem are: >=20 > f0000000-fed8ffff : PCI Bus 0000:00 > =C2=A0 faf00000-fb7fffff : PCI Bus 0000:01 > =C2=A0=C2=A0=C2=A0=C2=A0fafe0000-faffffff : 0000:01:01.0 > =C2=A0=C2=A0=C2=A0=C2=A0fb000000-fb7fffff : 0000:01:01.0 >=20 > Does it help? Is the change of type expected? Is it not a problem that > one of the ranges is overlapping with 2 other ranges? >=20 I debugged this problem with an AST 2000. What happens is that the vesafb driver attaches first to the graphics device. It disables write-combining and falls back to uncached access; unless the kernel has been booted with video=3Dvesafb:mtrr:3. Then it will set-up WC correctly.= The respective code is at [1]. Best regards Thomas [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/d= rivers/video/fbdev/vesafb.c?h=3Dv4.20-rc2#n415 --=20 Thomas Zimmermann Graphics Driver Developer SUSE Linux GmbH, Maxfeldstr. 5, D-90409 N=C3=BCrnberg Tel: +49-911-74053-0; Fax: +49-911-7417755; https://www.suse.com/ SUSE Linux GmbH, GF: Felix Imend=C3=B6rffer, Jane Smithard, Graham Norton, HRB 21284 (AG N=C3=BCrnberg) --Rn4ndp8dEZpMy3RT5hxOPCcvAIMetoyR9-- --qe8FfTZQBr9r2XWiH4uNUyamIlp6fkMZq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEchf7rIzpz2NEoWjlaA3BHVMLeiMFAlvp1iAACgkQaA3BHVML eiN49wgAk0rSqr54QvlZ0mMLaxY/ErhD8qNw7dzYD0hUUMQu7H+4VtKD70cMzGOA Fcsm7PqTvaLWW/aIQGDjrmws1l5KUA6ObgAM8L/0am5HM8gmuwRvxLcFNsivUV+y RkDhYbsZatBFUeIJJBOKoTOmT5cbyTM5in2I+2I/VfY3cCs0qBB/u3I/Ttw9kywR rxEkytSvv6Y+NKOR1kAI13LymMjZ4RD/m4RVEgc5YxvroHw6L/ciUGs54AUDs9hx rDtcJ5zagv5UefmlxxCVb3SF6BdcNU97Fx9MOIxFVszKyi6bmOvoXpjr0yl/yNCY bNBojj0QbPyJHznqrmCImdH9NdGkxg== =Zfru -----END PGP SIGNATURE----- --qe8FfTZQBr9r2XWiH4uNUyamIlp6fkMZq--