[PATCH 2/2] powerpc/mm: Ensure "special" zones are empty

[Balbir Singh]

On Thu, May 5, 2016 at 4:24 PM, Oliver O'Halloran <oohall at gmail.com> wrote:
> The mm zone mechanism was traditionally used by arch specific code to
> partition memory into allocation zones. However there are several zones
> that are managed by the mm subsystem rather than the architecture. Most
> architectures set the max PFN of these special zones to zero, however on
> powerpc we set them to ~0ul. This, in conjunction with a bug in
> free_area_init_nodes() results in all of system memory being placed
> being placed in ZONE_DEVICE when enabled. Device memory cannot be used
> for regular kernel memory allocations so this will cause a kernel panic at
> boot.
>
> Given the planned addition of more mm managed zones (ZONE_CMA) we should
> aim to be consistent with every other architecture and set the max PFN
> for these zones to zero
>
> Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
> ---
>

Reviewed-by: Balbir Singh <bsingharora at gmail.com>