Re: [PATCH] ac7 Athlon-SMP

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Mon Jun 05 2000 - 19:00:16 EST


> How about moving the in_interrupt() test into
> out_of_line_copy? The objection is that that's the case
> where you really want it fast.

It really wants to be inline code. It should come out very small.

> AMD says 3DNow PREFETCH is ok in interrupts, so is that test
> even necessary? It might be worthwhile to issue a prefetch
> before doing anything else, unless there are lots of really

You could stick a prefetch in early yes. But small copies are often
L1->L1 so its a loss.

As to the general in_interrupt case the problem is that you need to save
the FPU context and restore it when you do 3DNow/MMX2 stuff

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