Re: [PATCH] Mantaining turnstile aligned to 128 bytes in i386 CPUs

Maybe even someone finds a way to get optimized versions of memcpy in
the kernel :)

I was thinking: AFAIK the only major stopper is context saving of the
various "auxiliary" registers - FPU, MMX, SSE, right? But is it an
all-or-nothing situation? I.e. does it make sense (can it be done?) to
just elect to save the MMX context? (AFAIK they are different registers
than SSE, but overlay FPU registers?) The idea is to save something
smaller than the full set.

It makes a huge difference in a proprietary file serving appliance
that I know of. However, past measurements on FreeBSD have supposedly
indicated that it isn't that big win as a result of increased context
switch time.

-Kip
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