Re: efi_memmapwalk re-write (please test)

[Martin Hicks <mort@sgi.com>]

On Tue, Sep 06, 2005 at 01:48:11PM -0700, Luck, Tony wrote:
> I cleaned up my find_memmap_space() to do the right thing (allocate
> from a block of memory that will be used by the kernel).  I also
> had a couple of bugs in my code to find/divide all the memory
> between WB:kernel and UC:uncached-allocator.
> 
> Tested on tiger and zx1 (N.B. it didn't find any trimmed off scraps
> of memory that could be used as uncached on zx1).

So its really close on sn2.  I'm not sure exactly what's going wrong,
but with the new efi_memmap_walk stuff something is getting clobbered, I
think.

The efivars.c driver is looping through all the efi vars more than once,
causing efivar_create_sysfs_entry() to croak on the kobject_add() and
return -EEXIST during the first attempt to register a duplicate
variable.

This happens on an sn2 kernel without the Cross partition stuff compiled
(eliminating the uncached allocator from being the culprit).

I stuck KDB into the kernel and it doesn't crash anymore so I'm not sure
what the problem is :-/

> *) still passes region 6 addresses in efi_memmap_walk_uc() case, but
> could easily revert to physical addresses.  Comments?  Jes?  Martin?
> 

I think we can work with this either way.

Attached is a very small patch to find the uncached memory on SN2.

mh

-- 
Martin Hicks   ||   Silicon Graphics Inc.   ||   mort@sgi.com