Aaron Pace wrote:
In MMU_init of arch/powerpc/mm/init_32.c, where the current code sets
lmb.memory.cnt to zero, I instead walk through the memory regions and
call lmb_reserve for each chunk of memory that lies in a 'hole'.
There are then some minor fixups to make sure that total_memory and
total_highmem get the right numbers.  This small change allows all
four gigabytes of memory to be accessed and used in my tests.

Am I missing something obvious?

The main downsides that I see are wasted memory for bookkeeping of the hole (how acceptable this is depends on how large the hole is relative to the size of RAM -- it's a tradeoff against speed of looking up page structs), and that the reserved area may still be mapped in the TLB without the guarded bit set.

-Scott

_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev

Reply via email to