From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756438Ab3KHIUC (ORCPT ); Fri, 8 Nov 2013 03:20:02 -0500 Received: from mail-lb0-f174.google.com ([209.85.217.174]:60874 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752743Ab3KHITz (ORCPT ); Fri, 8 Nov 2013 03:19:55 -0500 From: Mikael Pettersson MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <21116.40614.511367.579373@gargle.gargle.HOWL> Date: Fri, 8 Nov 2013 09:19:50 +0100 To: Yinghai Lu Cc: Mikael Pettersson , Linux Kernel Mailing List Subject: Re: [BUG?] mtrr sanitizer fails on Latitude E6230 In-Reply-To: References: <21114.2315.610902.200164@gargle.gargle.HOWL> <21115.20118.72541.74924@gargle.gargle.HOWL> X-Mailer: VM 8.1.2 under 24.1.1 (x86_64-redhat-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Yinghai Lu writes: > On Thu, Nov 7, 2013 at 12:25 AM, Mikael Pettersson wrote: > > Yinghai Lu writes: > > > On Wed, Nov 6, 2013 at 1:16 AM, Mikael Pettersson wrote: > > > > I recently got a Dell Latitude E6230 (Ivy Bridge i7-3540M) and noticed that > > > > the mtrr sanitizer failed on it: > > > > > > > > === snip === > > > > Linux version 3.12.0 (mikpe@barley) (gcc version 4.8.3 20131017 (prerelease) (GCC) ) #1 SMP Wed Nov 6 09:46:02 CET 2013 > > > > Command line: ro root=LABEL=/ resume=/dev/sda2 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=sv-latin1 > > > ... > > > gran_size: 8M chunk_size: 64M num_reg: 9 lose cover RAM: 6M > > > ... > > > > mtrr_cleanup: can not find optimal value > > > > please specify mtrr_gran_size/mtrr_chunk_size > > > > === snip === > > > > > > > > For now I'm disabling the mtrr sanitizer in this machine's kernel. > > > > > > Can you try to boot with "mtrr_gran_size=8m mtrr_chunk_size=64m" ? > > > > That results in: > > > > reg 0, base: 0GB, range: 8GB, type WB > > reg 1, base: 8GB, range: 512MB, type WB > > reg 2, base: 3584MB, range: 512MB, type UC > > reg 3, base: 3520MB, range: 64MB, type UC > > reg 4, base: 3512MB, range: 8MB, type UC > > reg 5, base: 8688MB, range: 16MB, type UC > > reg 6, base: 8680MB, range: 8MB, type UC > > reg 7, base: 8678MB, range: 2MB, type UC > > total RAM covered: 8094M > > gran_size: 8M chunk_size: 64M num_reg: 9 lose cover RAM: 6M > > New variable MTRRs > > reg 0, base: 0GB, range: 2GB, type WB > > reg 1, base: 2GB, range: 1GB, type WB > > reg 2, base: 3GB, range: 256MB, type WB > > reg 3, base: 3328MB, range: 128MB, type WB > > reg 4, base: 3456MB, range: 64MB, type WB > > reg 5, base: 3512MB, range: 8MB, type UC > > reg 6, base: 4GB, range: 4GB, type WB > > reg 7, base: 8GB, range: 512MB, type WB > > reg 8, base: 8672MB, range: 32MB, type UC > > e820: update [mem 0xdb800000-0xffffffff] usable ==> reserved > > e820: update [mem 0x21e000000-0x21e5fffff] usable ==> reserved > ... > >> modified: [mem 0x000000021e000000-0x000000021e5fffff] reserved > > that is right, it throw 6M away. > > Did you notice any slowness or speeding for x window? I'm not noticing any change. i915 kernel driver + xorg's intel driver. > What does /proc/mtrr look like after xwindow is started? reg00: base=0x000000000 ( 0MB), size= 2048MB, count=1: write-back reg01: base=0x080000000 ( 2048MB), size= 1024MB, count=1: write-back reg02: base=0x0c0000000 ( 3072MB), size= 256MB, count=1: write-back reg03: base=0x0d0000000 ( 3328MB), size= 128MB, count=1: write-back reg04: base=0x0d8000000 ( 3456MB), size= 64MB, count=1: write-back reg05: base=0x0db800000 ( 3512MB), size= 8MB, count=1: uncachable reg06: base=0x100000000 ( 4096MB), size= 4096MB, count=1: write-back reg07: base=0x200000000 ( 8192MB), size= 512MB, count=1: write-back reg08: base=0x21e000000 ( 8672MB), size= 32MB, count=1: uncachable /Mikael