Messages in this thread |  | | Date | Sat, 10 Feb 2001 19:18:00 +0100 | From | Manfred Spraul <> | Subject | Re: [beta patch] SSE copy_page() / clear_page() |
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Manfred Spraul wrote: > > copy_*_user is probably not worth the effort for a Pentium III, but even > for that function I don't see a problem with SSE, as long as > > * the clobbered registers are stored on the stack (and not in > thread.i387.fxsave) > * the SSE/SSE2 instructions can't cause SIMD exceptions. > * noone saves the fpu state into thread.i387.fxsave from interrupts / > softirq's. Currently it's impossible, but I haven't checked Montavista's > preemptive kernel scheduler. > I overlooked one restriction: * you must not schedule() with the "wrong" sse registers: switch_to() saves into i387.fxsave.
This means that copy_*_user isn't that simple.
-- Manfred - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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