From: Ben Hutchings <redacted>
Date: Mon, 21 Feb 2011 18:19:55 +0000

On Wed, 2010-09-01 at 18:32 -0700, David Miller wrote:

quoted

2) TX queue datastructures in the driver get reallocated using
   memory in that NUMA domain.

I've previously sent patches to add an ethtool API for NUMA control,
which include the option to allocate on the same node where IRQs are
handled.  However, there is currently no function to allocate
DMA-coherent memory on a specified NUMA node (rather than the device's
node).  This is likely to be beneficial for event rings and might be
good for descriptor rings for some devices.  (The implementation I sent
for sfc mistakenly switched it to allocating non-coherent memory, for
which it *is* possible to specify the node.)

The thing to do is to work with someone like FUJITA Tomonori on this.

It's simply a matter of making new APIs that take the node specifier,
have the implementations either make use of or completely ignore the node,
and have the existing APIs pass in "-1" for the node or whatever the
CPP macro is for this :-)