From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751439AbeDFAa7 (ORCPT ); Thu, 5 Apr 2018 20:30:59 -0400 Received: from mail-qk0-f170.google.com ([209.85.220.170]:38359 "EHLO mail-qk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751179AbeDFAa6 (ORCPT ); Thu, 5 Apr 2018 20:30:58 -0400 X-Google-Smtp-Source: AIpwx48G7IpI2znXruNIk817rgnbY73kXxGTvSUmN3lUkabIlJuCx2b5VBIR9kIksW8fJObmMQtDhA== To: airlied@linux.ie, alexander.deucher@amd.com, christian.koenig@amd.com, Felix.Kuehling@amd.com, labbott@redhat.com, akpm@linux-foundation.org, michel.daenzer@amd.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org From: Jean-Marc Valin Subject: AMD graphics performance regression in 4.15 and later Message-ID: Date: Thu, 5 Apr 2018 20:30:55 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I noticed a serious graphics performance regression between 4.14 and 4.15. It is most noticeable with Firefox (tried FF57 through FF60) and causes scrolling to be really choppy/sluggish. I've confirmed that the problem is also there on 4.16, while 4.13 works fine. After a bisection, I've narrowed the regression down to this commit: commit 648bc3574716400acc06f99915815f80d9563783 Author: Christian König Date: Thu Jul 6 09:59:43 2017 +0200 drm/ttm: add transparent huge page support for DMA allocations v2 Some details about my system: Distro: Fedora 27 (up-to-date) Video: MSI Radeon RX 560 AERO CPU: Dual-socket Xeon E5-2640 v4 (20 cores total) RAM: 128 GB ECC As a comparison, when running Firefox with 4.15 on a Lenovo W540 laptop (with Intel graphics only) the responsiveness is much better then what I'm getting on the Xeon machine above with the Radeon card, so this really seems to be an AMD-only issue. Any way to fix the issue? Thanks, Jean-Marc