Thread (7 messages) 7 messages, 3 authors, 2016-06-21

Re: [v2] powerpc/mm: Ensure "special" zones are empty

From: Michael Ellerman <mpe@ellerman.id.au>
Date: 2016-06-21 00:40:58
Also in: linuxppc-dev

On Wed, 2016-11-05 at 09:22:18 UTC, Oliver O'Halloran 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 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@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Cc: linux-mm@kvack.org
Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/3079abe555511031e2ba5d1e21

cheers

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help