Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987AbZIZBr6 (ORCPT ); Fri, 25 Sep 2009 21:47:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752858AbZIZBry (ORCPT ); Fri, 25 Sep 2009 21:47:54 -0400 Received: from mail-px0-f194.google.com ([209.85.216.194]:62589 "EHLO mail-px0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750AbZIZBrv (ORCPT ); Fri, 25 Sep 2009 21:47:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=NHE5AZhnH8QH+v84brXQ1CKgneuPqYZcy4uD6GK4t2yF+d5tsjXRZVHZfMncfTMWXg 5N5U8dK/EjUzFFbOeKbfibGkilhAOirkYajccUjJg37lnfeQ2uVioeJbaa4M7pz6mtYh 5Yl7bZepEqFYorj9VJDXmrF7Fzn4hxcIt/VKs= MIME-Version: 1.0 In-Reply-To: <501db8660909251802hacbaf04wb8dc1734fa523d34@mail.gmail.com> References: <501db8660909251509i3eb6cb20i74337928e0708410@mail.gmail.com> <200909260051.34541.elendil@planet.nl> <501db8660909251802hacbaf04wb8dc1734fa523d34@mail.gmail.com> Date: Fri, 25 Sep 2009 18:47:55 -0700 Message-ID: <86802c440909251847p421d6523ra40c59e724d566fb@mail.gmail.com> Subject: Re: Regression: kernels since 2.6.26 are unusably slow From: Yinghai Lu To: Aneurin Price Cc: Frans Pop , linux-kernel@vger.kernel.org, Yinghai Lu , Ingo Molnar , Thomas Gleixner Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2463 Lines: 47 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 YH -- 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/