Messages in this thread | | | Date | Fri, 29 Jun 2012 15:29:31 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [Xen-devel] [PATCH] x86 fixes for 3.3 impacting distros (v1). |
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On 06/29/2012 02:52 PM, Cyclonus J wrote: > > Peter, > > hmm, It looks like option 1 doesn't have any perf regression, but it is still > not acceptable? That is fine. If you prefer to have a software PAT table lookup, could you provide > some details so I can try to get something align that direction? >
It has no perf regression, but it really buries deep in the code a strange abstraction which only happens to work on Xen and is confusing as hell.
The idea with a software PAT table is that the PAT numbers used by the kernel should come from a table in the kernel instead of being hard-coded. That might take some work, and it remains to be seen if it is practical.
It *may* be that we need to hard-code 0 as WB, still, but that should be true on any sane platform.
-hpa
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