Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753117AbZIZCtK (ORCPT ); Fri, 25 Sep 2009 22:49:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752809AbZIZCtJ (ORCPT ); Fri, 25 Sep 2009 22:49:09 -0400 Received: from mail-yw0-f174.google.com ([209.85.211.174]:58368 "EHLO mail-yw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752758AbZIZCtJ (ORCPT ); Fri, 25 Sep 2009 22:49:09 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=QMFdk7o0ec3+VZTqaBZUaj/+Iqvxd6JaGgFi1UG0rQjFvgiEaB51r9DKAGfgS5gyr/ fGaiCH8B8wr0quNtxtcjoQo+Z7vLYXeh0DNzmk4h8TC7N6j42ynoFwg9TN6LbHoC5Otx 9/HqLXeB8uaEQf+/5TztSJj9Aybp3AwQqiqrk= Message-ID: <4ABD8124.9060108@gmail.com> Date: Fri, 25 Sep 2009 20:49:08 -0600 From: Robert Hancock User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Yinghai Lu CC: Aneurin Price , Frans Pop , linux-kernel@vger.kernel.org, Yinghai Lu , Ingo Molnar , Thomas Gleixner Subject: Re: Regression: kernels since 2.6.26 are unusably slow References: <501db8660909251509i3eb6cb20i74337928e0708410@mail.gmail.com> <200909260051.34541.elendil@planet.nl> <501db8660909251802hacbaf04wb8dc1734fa523d34@mail.gmail.com> <86802c440909251847p421d6523ra40c59e724d566fb@mail.gmail.com> In-Reply-To: <86802c440909251847p421d6523ra40c59e724d566fb@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2661 Lines: 49 On 09/25/2009 07:47 PM, Yinghai Lu wrote: > On Fri, Sep 25, 2009 at 6:02 PM, Aneurin Price wrote: > >> Hmm. Looking at dmesg for a 'working' kernel includes an interesting part which >> I foolishly forgot to save, saying that the last 512MB of memory is >> inaccessible (I was wondering where that last half-gig had gone :-)). I can go >> and check exactly what it says, but I don't have the energy left for any more >> reboots today. Anyway, that prompted me to try booting with mem=7168 - and that >> makes the problem go away. Perhaps that will shed some light on things. > > [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009e800 (usable) > [ 0.000000] BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved) > [ 0.000000] BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) > [ 0.000000] BIOS-e820: 0000000000100000 - 00000000dfee0000 (usable) > [ 0.000000] BIOS-e820: 00000000dfee0000 - 00000000dfee3000 (ACPI NVS) > [ 0.000000] BIOS-e820: 00000000dfee3000 - 00000000dfef0000 (ACPI data) > [ 0.000000] BIOS-e820: 00000000dfef0000 - 00000000dff00000 (reserved) > [ 0.000000] BIOS-e820: 00000000f0000000 - 00000000f4000000 (reserved) > [ 0.000000] BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved) > [ 0.000000] BIOS-e820: 0000000100000000 - 0000000220000000 (usable) > [ 0.000000] DMI 2.4 present. > [ 0.000000] last_pfn = 0x220000 max_arch_pfn = 0x400000000 > [ 0.000000] MTRR default type: uncachable > [ 0.000000] MTRR fixed ranges enabled: > [ 0.000000] 00000-9FFFF write-back > [ 0.000000] A0000-BFFFF uncachable > [ 0.000000] C0000-CDFFF write-protect > [ 0.000000] CE000-EFFFF uncachable > [ 0.000000] F0000-FFFFF write-through > [ 0.000000] MTRR variable ranges enabled: > [ 0.000000] 0 base 100000000 mask FE0000000 write-back > [ 0.000000] 1 base 100000000 mask F00000000 write-back > [ 0.000000] 2 base 000000000 mask F00000000 write-back > [ 0.000000] 3 base 0E0000000 mask FE0000000 uncachable > [ 0.000000] 4 base 0DFF00000 mask FFFF00000 write-through > [ 0.000000] 5 disabled > [ 0.000000] 6 disabled > [ 0.000000] 7 disabled > > looks like your MTRR has some problem, and with that WRITE-THROUGH > there, the trimming e820 will not happen You might want to see if there's a BIOS update available for that system/motherboard.. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/