[Crash-utility] [PATCH] CONFIG_SPARSEMEM for s390(x)

[Dave Anderson]

David J. Wilder wrote:
> On Tue, 2008-08-12 at 17:12 +0200, Michael Holzheu wrote:
> 
>>Hi Dave,
>>
>>When starting crash on s390(x) with CONFIG_SPARSEMEM enabled we get the
>>following error message:
>>
>>crash: CONFIG_SPARSEMEM kernels not supported for this architecture
>>
>>The following patch fixes this problem, but I am not sure, if I set
>>_MAX_PHYSMEM_BITS to the correct value (I used 31 for s390 and 64 for
>>s390x). Could you please explain the meaning of _MAX_PHSYSMEM_BITS?
>>---
>>
> 
> 
> _MAX_PHSYSMEM_BITS is the number of physical addressing bits provided by
> the hardware.  It is defined as MAX_PHSYSMEM_BITS in asm/sparsemem.h.
> 

Yeah -- I've been having a side discussion with Michael about this,
re: the need for his patch to use the correct MAX_PHYSMEM_BITS values
from sparsemem.h, as well as to initialize machdep->section_size_bits
with the appropriate _SECTION_SIZE_BITS values from the same file.

Dave