On Mon, 2007-10-15 at 13:07 +0200, Andi Kleen wrote:
The problem exist also on ppc, and afaik, is due to the line being in
the cache at all (either dirty (write) or not (read)), thus causing the
snoop logic to hit, that is what's causing the problem vs. non cached
accesses.
Also, on some processors, the simple fact of having the page mapped can
cause the CPU to prefetch from it even if it's not actually accessed
(speculative prefetch can cross page boundaries if things are mapped).
Ben.
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