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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 4F3C8C43441 for ; Mon, 12 Nov 2018 16:41:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F68A2241E for ; Mon, 12 Nov 2018 16:41:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1F68A2241E 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 S1729921AbeKMCfs (ORCPT ); Mon, 12 Nov 2018 21:35:48 -0500 Received: from mx2.suse.de ([195.135.220.15]:60348 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728018AbeKMCfs (ORCPT ); Mon, 12 Nov 2018 21:35:48 -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 53D5BB174; Mon, 12 Nov 2018 16:41:46 +0000 (UTC) Message-ID: <1542040904.2661.35.camel@suse.de> Subject: Re: Performance regression in ast drm driver From: Jean Delvare To: Takashi Iwai Cc: David Airlie , christian.koenig@amd.com, dri-devel , linux-kernel Date: Mon, 12 Nov 2018 17:41:44 +0100 In-Reply-To: References: <20181101162707.598c1718@endymion> <20181108130509.3b2d42ff@endymion> <1542033367.2661.33.camel@suse.de> Organization: Suse Linux Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2018-11-12 at 15:45 +0100, Takashi Iwai wrote: > On Mon, 12 Nov 2018 15:36:07 +0100, > Jean Delvare wrote: > > 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: > > > > uncached-minus @ 0xfafe0000-0xfb000000 > > uncached-minus @ 0xfb000000-0xfb005000 > > write-combining @ 0xfb005000-0xfb584000 > > > > After the commit, we have: > > > > uncached-minus @ 0xfafe0000-0xfb000000 > > uncached-minus @ 0xfb000000-0xfb005000 > > uncached-minus @ 0xfb000000-0xfb800000 > > uncached-minus @ 0xfb005000-0xfb584000 > > Just to be sure: > could you double-check whether you're checking the right order > (i.e. not checking against the revert)? The change above looks > illogical from what I can see from the commit... Yes, I double checked and can only confirm what I wrote above. However while checking I noticed another strange thing: the contents of pat_memtype_list depend on whether I'm reading the file from an xterm or from the text console (Ctrl+Alt+F2). So I summarize again: Commit "drm/drivers: add support for using the arch wc mapping API" APPLIED, reading pat_memtype_list from the text console: uncached-minus @ 0xfafe0000-0xfb000000 uncached-minus @ 0xfb000000-0xfb005000 uncached-minus @ 0xfb000000-0xfb800000 uncached-minus @ 0xfb005000-0xfb584000 Commit "drm/drivers: add support for using the arch wc mapping API" APPLIED, reading pat_memtype_list from an xterm: uncached-minus @ 0xfafe0000-0xfb000000 uncached-minus @ 0xfb000000-0xfb005000 uncached-minus @ 0xfb000000-0xfb800000 Commit "drm/drivers: add support for using the arch wc mapping API" REVERTED, reading pat_memtype_list from the text console: uncached-minus @ 0xfafe0000-0xfb000000 uncached-minus @ 0xfb000000-0xfb005000 write-combining @ 0xfb005000-0xfb584000 Commit "drm/drivers: add support for using the arch wc mapping API" REVERTED, reading pat_memtype_list from an xterm: uncached-minus @ 0xfafe0000-0xfb000000 uncached-minus @ 0xfb000000-0xfb005000 If you don't find it logical, remember that if things were the way they are supposed to be, customers and myself would not be reporting this bug ;-) -- Jean Delvare SUSE L3 Support