Re: [PATCH] x86: add SSE-based copy_page()

["Jan Beulich" <jbeulich@novell.com>]

>>> Keir Fraser <keir.fraser@eu.citrix.com> 13.01.09 09:13 >>>
>Seems like unless we dynamically choose the copy routine, we're better off
>without the SSE2 alternative. Shall I revert it then?

I'd vote for not reverting it - Xen itself doesn't use copy_page() much, and
whether a domain wants to use MMUEXT_COPY_PAGE could be decided by
it based on its own judgement.

Ultimately we should improve it as you say to dynamically select the copy
method, but then the question really is whether to base the selection on
static CPU information, best cold, or best warm cache performance.

Jan