[Xen-devel] [PATCH] fix zone-over-node preference when allocating memory

Andre Przywara
Fri, 21 Dec 2007 22:27:59 -0000

When Xen allocates the guest''s memory, it will try to use non-DMA-able
zones first (probably because they are less precious). If there are no
such pages available on a certain node, Xen will revert to allocating
low pages from another node and thus ignoring the node-preference. This
patch fixes this by first checking if non-DMA pages are available on a
node and reverting to DMA-able pages if not. This fixes incorrect NUMA
memory allocation on nodes with memory below the DMA border (4GB on
x86-64, affects for instance dual-node machines with 4gig on each node).

Andre.

P.S. This fix was already part of my NUMA guest patches back in August,
this is just an extract of these.

Signed-off-by: Andre Przywara <andre.przywara@amd.com>

--
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
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