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    SubjectRe: [PATCH] [1/1] CPA: Flush the caches when setting pages not present v2

    > This is suboptimal though, as it will trigger a wbinvd() everytime
    > when we hit a non present pte in a range, whether we did set the entry
    > in question to not present or not.

    Do you think that's common? I considered this while writing the code,
    but figured it was just a oddball case not worth caring about.

    DEBUG_PAGEALLOC does not call this normally anyways and people
    should not call this for unallocated mappings anyways.

    > The gart code unmapping is a special case. This only happens during
    > boot, so adding a wbinvd() to the gart code is solving this issue
    > without imposing it on other use cases.
    > Another solution for this would be to change the mapping to uncached
    > before unmapping, so we could avoid the wbinvd() completely.

    That will work for pci-gart, but not for some future users of set_memory_np()
    I plan to submit (they run potentially with multiple CPUs online and doing callbacks
    there would be quite ugly). So I would prefer if you kept some variant of my original patch.


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