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    Subjecthugetlb page migration vs. overcommit
    Hi,
    is there any reason why we enforce the overcommit limit during hugetlb
    pages migration? It's in alloc_huge_page_node->__alloc_buddy_huge_page
    path. I am wondering whether this is really an intentional behavior.
    The page migration allocates a page just temporarily so we should be
    able to go over the overcommit limit for the migration duration. The
    reason I am asking is that hugetlb pages tend to be utilized usually
    (otherwise the memory would be just wasted and pool shrunk) but then
    the migration simply fails which breaks memory hotplug and other
    migration dependent functionality which is quite suboptimal. You can
    workaround that by increasing the overcommit limit.

    Why don't we simply migrate as long as we are able to allocate the
    target hugetlb page? I have a half baked patch to remove this
    restriction, would there be an opposition to do something like that?
    --
    Michal Hocko
    SUSE Labs

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