Messages in this thread | | | Subject | Re: pci-gart_64.c: could we get better explanation? | From | Benjamin Herrenschmidt <> | Date | Tue, 27 May 2008 05:51:39 +1000 |
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On Mon, 2008-05-26 at 20:47 +0200, Pavel Machek wrote: > Hi! > > +++ b/arch/x86/kernel/pci-gart_64.c > @@ -774,6 +778,7 @@ #endif > > /* > * Try to workaround a bug (thanks to BenH) > * Set unmapped entries to a scratch page instead of 0. > * Any prefetches that hit unmapped entries won't get an bus abort > > Could someone explain? Which bug is being worked around? CPUs > prefetching over NULL?
P2P bridge prefetching on DMA reads.
Ben.
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