Messages in this thread |  | | | Date | Fri, 17 Dec 2010 11:15:05 -0500 | | From | Vivek Goyal <> | | Subject | Re: kdump broken on 2.6.37-rc4 |
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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 <ebiederm@xmission.com> > >>>> 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
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