Messages in this thread | | | From | Andy Lutomirski <> | Date | Wed, 10 Sep 2014 13:31:27 -0700 | Subject | Re: [PATCH v2 2/6] x86, mm, pat: Change reserve_memtype() to handle WT |
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On Wed, Sep 10, 2014 at 1:14 PM, H. Peter Anvin <hpa@zytor.com> wrote: > On 09/10/2014 12:30 PM, Toshi Kani wrote: >> >> When WT is unavailable due to the PAT errata, it does not fail but gets >> redirected to UC-. Similarly, when PAT is disabled, WT gets redirected >> to UC- as well. >> > > But on pre-PAT hardware you can still do WT. >
Using MTRRs? /me shudders, although I suppose this would be okay for NV-DIMMs as long as you map the whole thing WT.
One of these days I'll finish excising mtrr_add from everything outside arch/x86. I already killed it in all modern graphics drivers :)
--Andy
> -hpa >
-- Andy Lutomirski AMA Capital Management, LLC
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