On Wed, Sep 10, 2014 at 1:14 PM, H. Peter Anvin <hpa@xxxxxxxxx> 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>