Re: [PATCH] mm: introduce numa_zero_pfn

[Andi Kleen]

> I would expect a processor to fetch the zero page cachelines from the l3
> cache from other sockets avoiding memory transactions altogether. The zero
> page is likely in use somewhere so no typically no memory accesses should
> occur in a system.

It depends on how effectively the workload uses the caches. If something
is a cache pig of the L3 cache, then even shareable cache lines may need
to be refetched regularly.

But if your workloads spends a significant part of its time reading
from zero page read only data there is something wrong with the workload.

I would do some data profiling first to really prove that is the case.

-Andi
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