Re: [Xen-devel] using PageForeign for pte allocation vs. shortcutting __pte_free_tlb()

[Gerd Hoffmann <kraxel@xxxxxxx>]

Jan Beulich wrote:
>>>> Gerd Hoffmann <kraxel@xxxxxxx> 09.01.07 11:51 >>>
>> Jan Beulich wrote:
>>> In the course of trying to get CONFIG_HIGHPTE to work I stumbled across this
>>> inconsistency between i386 and x86-64 Linux: i386 uses SetPageForeign() in
>>> (one the non-highpte) case of pte_alloc_one(), and leaves intact native's
>>> definition of __pte_free_tlb(), whereas x86-64 doesn't use the former but
>>> shortcuts the latter to just invoke pte_free(). Obviously it would be nice 
>>> for
>>> these two to be consistent,
>> x86-64 has no HIGHMEM zone, thus CONFIG_HIGHPTE has no effect (I'm
>> surprised it exists in the first place ...).
> 
> Of course (and no, such a config option doesn't exist for x86-64), but what
> relation does this have to the question asked?

guess (not having looked at the code at all) i386 does that because it
needs disturgish high and non-high ptes, whereas x86-64 simply has no
need for that, so I don't see the point in trying to make them
consistent ...

cheers,
  Gerd

-- 
Gerd Hoffmann <kraxel@xxxxxxx>

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