Messages in this thread | | | Date | Tue, 20 Feb 2001 21:52:16 +0100 | From | Pavel Machek <> | Subject | Re: [beta patch] SSE copy_page() / clear_page() |
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> > > + __asm__ __volatile__( > > > + "mov %1, %0\n\t" > > > + : "=r" (i) > > > + : "r" (kaddr+offset)); /* load tlb entry */ > > > + for(i=0;i<size;i+=64) { > > > + __asm__ __volatile__( > > > + "prefetchnta (%1, %0)\n\t" > > > + "prefetchnta 32(%1, %0)\n\t" > > > + : /* no output */ > > > + : "r" (i), "r" (kaddr+offset)); > > > + } > > > + } > > > left = __copy_to_user(desc->buf, kaddr + offset, size); > > > kunmap(page); > > > > This seems bogus -- you need to handle faults -- > > i.e. __prefetchnta_to_user() ;-). > > It wants wrapping nicely. A generic prefetch and prefetchw does help some other > cases (scheduler for one). > > Does the prefetch instruction fault on PIII/PIV then - the K7 one appears not > to be a source of faults
My fault. I was told that prefetch instructions are always non-faulting.
Pavel
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