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
Tel: +49 351 277-84917
----to satisfy European Law for business letters:
AMD Saxony Limited Liability Company & Co. KG,
Wilschdorfer Landstr. 101, 01109 Dresden, Germany
Register Court Dresden: HRA 4896, General Partner authorized
to represent: AMD Saxony LLC (Wilmington, Delaware, US)
General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy
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
Tel: +49 351 277-84917
----to satisfy European Law for business letters:
AMD Saxony Limited Liability Company & Co. KG,
Wilschdorfer Landstr. 101, 01109 Dresden, Germany
Register Court Dresden: HRA 4896, General Partner authorized
to represent: AMD Saxony LLC (Wilmington, Delaware, US)
General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy