Re: [PATCH v2] MIPS: Kernel crashes on boot with SPARSEMEM + HIGHMEM enabled

[David Daney <ddaney@caviumnetworks.com>]

On 04/01/2011 11:41 AM, Michael Sundius wrote:
> David Daney wrote:
> > I think this may do the same thing as my patch:
> >
> > http://patchwork.linux-mips.org/patch/1988/
> >
> > Although my patch had different motivations, and changes some other
> > things around too.
> >
> > David Daney
> I'm not really sure why your kernel or initrd would be in memory was not
> within
> the range that had been accounted for. are you saying its in high mem?
Well the memory initialization code has a bunch of weird rules built in 
that prevent some memory from being used.
For example if the kernel resides in a different SPARSE page than the 
rest of memory bad things happen because memory_present() was not called 
on something that is later freed (when init memory is released).
If I try to put an initrd at a high physical address, the memory below 
that is not usable.
My three patches try to make some sense out of the whole thing.

David Daney