Allow memory to be allocated on a specified node. Use it in the
perf ring-buffer code.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
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I was looking at the perf ringbuffer code for other reasons, and I noticed
that everything else gets allocated on the specified node ... except
there's no way to do this for vmalloc. I assume it'd be helpful here too.