Messages in this thread | | | Subject | Re: [RFC Patch] use MTRR for write combining if PAT is not available | From | Suresh Siddha <> | Date | Mon, 19 Oct 2009 14:49:27 -0700 |
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On Mon, 2009-10-19 at 08:31 -0700, Ingo Molnar wrote: > * Thomas Schlichter <thomas.schlichter@web.de> wrote: > > > I don't think this is a good idea, Robert Hancock wrote there may be > > millions of such Laptops (Core Solo/Duo erratum AE7, Pentium M erratum > > Y31) : > > > > http://marc.info/?l=linux-kernel&m=125537136105246&w=2 > > > > > or Perhaps just try to add mtrr only for the pci mmap case like the > > > 4th patch in this series.. > > > > I'd prefer this! ;-) > > Hm, we could perhaps do that - but i think we should only do that on > systems that have PAT disabled. > > Which brings up the question of how to properly QA such a narrow segment > of the market. Maybe disabling CONFIG_X86_PAT should enable that logic > too.
Also, I think we can simplify and avoid mtrr_add_unaligned() and worry only about the pci mmap aligned cases etc. Those are the only interesting ones.
thanks, suresh
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