Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753539Ab0LQQP2 (ORCPT ); Fri, 17 Dec 2010 11:15:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:29800 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267Ab0LQQPZ (ORCPT ); Fri, 17 Dec 2010 11:15:25 -0500 Date: Fri, 17 Dec 2010 11:15:05 -0500 From: Vivek Goyal To: Yinghai Lu Cc: "H. Peter Anvin" , "Eric W. Biederman" , Stanislaw Gruszka , Ingo Molnar , Thomas Gleixner , Maxim Uvarov , linux-kernel@vger.kernel.org, Neil Horman Subject: Re: kdump broken on 2.6.37-rc4 Message-ID: <20101217161505.GB9568@redhat.com> References: <4D0663F0.2060103@kernel.org> <4D06783C.6040009@zytor.com> <20101214224135.GB19693@redhat.com> <20101215103954.GA2243@redhat.com> <4D09958D.2040907@kernel.org> <20101216143925.GA13870@redhat.com> <4D0A3E31.4000109@zytor.com> <4D0A4C51.3070008@kernel.org> <20101216220117.GA2485@redhat.com> <4D0A9986.4080209@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D0A9986.4080209@kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2307 Lines: 64 On Thu, Dec 16, 2010 at 02:58:14PM -0800, Yinghai Lu wrote: > On 12/16/2010 02:01 PM, Vivek Goyal wrote: > > On Thu, Dec 16, 2010 at 09:28:49AM -0800, Yinghai Lu wrote: > >> On 12/16/2010 08:28 AM, H. Peter Anvin wrote: > >>> On 12/16/2010 06:39 AM, Vivek Goyal wrote: > >>>> On Wed, Dec 15, 2010 at 08:29:01PM -0800, Yinghai Lu wrote: > >>>>> please check > >>>>> > >>>>> [PATCH] x86, crashkernel, 32bit: only try to get range under 512M > >>>>> > >>>>> Steanishlaw report kdump is 32bit is broken. > >>>>> > >>>>> in misc.c for decompresser, it will do sanity checking to make sure heap > >>>>> heap under 512M. > >>>> > >>>> Thanks Yinghai. I am wondering why on 32bit heap has to be with-in 512MB. > >>>> I think you are referring to following check in > >>>> arch/x86/boot/compressed/misc.c. > >>>> > >>>> if (end > ((-__PAGE_OFFSET-(512 <<20)-1) & 0x7fffffff)) > >>>> error("Destination address too large"); > >>>> > >>>> It was introduced here. > >>>> > >>>> commit 968de4f02621db35b8ae5239c8cfc6664fb872d8 > >>>> Author: Eric W. Biederman > >>>> Date: Thu Dec 7 02:14:04 2006 +0100 > >>>> > >>>> [PATCH] i386: Relocatable kernel support > >>>> > >>>> Eric, > >>>> > >>>> It has been long. By any chance would you remember where does above > >>>> constraint come from? > >>>> > >>> > >>> It might, in fact, be bogus; specifically a proxy for the fact that we > >>> need the kernel memory including bss and brk below the lowmem boundary, > >>> which isn't well-defined. > >> > >> the brk is complaining if i change that to > >> > >> if (end > ((-__PAGE_OFFSET-(128 <<20)-1) & 0x7fffffff)) > >> error("Destination address too large"); > >> > > > > Yinghai, > > > > On my system above change works fine and I can boot into second kernel. So > > it will boil down to knowing what are the exact constraints on heap for > > decompression and for 32bit can we allow heap upto 896MB or not. > > really? what is you CONFIG_PAGE_OFFSET? 0x40000000 or 0xc0000000? > I am using CONFIG_PAGE_OFFSET=0xC0000000 Thanks Vivek -- 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/