Re: [RFC] x86-64: Use SSE for copy_page and clear_page

[Andi Kleen]

michael@xxxxxxxxxxxxxxx writes:
>
> Key point: "using it". This normally involves writes to memory. Most
> applications don't commonly read memory that they haven't previously
> written to. (valgrind et al call that behaviour a "bug" :).
>
> Given that, I'd say you really don't want the page zero routines
> touching the cache.

Writing on a modern CPU requires reading first too to get the rest
of the cache line (provided you don't use write combing or uncached
accesses)

-Andi
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