Messages in this thread | | | Date | Fri, 14 Dec 2007 00:28:25 +0000 (GMT) | From | Dave Airlie <> | Subject | Re: [RFC PATCH 00/12] PAT 64b: PAT support for X86_64 |
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> Yes. It is that wonderful time of the year again. > No, no. We are not talking about holiday season or new year here. > > We are talking about one another rehash of "why we do not support PAT in x86" > question and series of patches that implement some PAT support before going > into hibernation again. Only difference is that we hope to take this little > further this time and may be really get this support into > upstream kernel soon.
Woot, PAT support: this time we mean it!!
I'll just give one comment after a reading your todo..
> * Do we need to allow RAM pages to be mapped as WC? If not, then > we don't need to follow the TLB flush mechanism (make pte not present, > flush, and set pte with new mapping) mentioned in section 10.12.4 of SDM > Vol3a.
Yes, the main use for GPUs is to have RAM pages mapped WC, and placed into a GART on the GPU side, currently for Intel IGD we are okay as the CPU can access the GPU GART aperture, but other chips exist where this isn't possible, I think poulsbo and possible some of the AMD IGPs..
Dave.
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