Re: [Xen-devel] [PATCH] linux/i386: allow CONFIG_HIGHPTE on i386

["Jan Beulich" <jbeulich@xxxxxxxxxx>]

>>> Keir Fraser <keir@xxxxxxxxxxxxx> 10.01.07 11:57 >>>
>On 10/1/07 09:57, "Jan Beulich" <jbeulich@xxxxxxxxxx> wrote:
>
>> The patch at once does away with the use of PageForeign on pte pages, to 
>> match
>> x86-64 and to reduce the delta to native.
>
>Is it actually safe to circumvent tlb_remove_page()? It does rather more
>than just free_page()! That's why I used a ForeignPage hook when writing the
>i386 code. It's certainly *not* safe to assume that whoever wrote that part
>of the x86/64 port understood all the ramifications of what they were doing.

Not really, as I understand it - it either frees the page (when the TLB is in 
fast
mode) or inserts the page into the gather list, bumping the contained pages
count and freeing all of them and flushing the hardware TLBs if exceeding the
threshold - the latter step is otherwise done from tlb_finish_mmu().

And - I asked about this inconsistency between i386 and x86-64 before
submitting the patch, with no useful responses...

Jan

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