• Hugh Dickins's avatar
    [PATCH] freepgt: hugetlb_free_pgd_range · 3bf5ee95
    Hugh Dickins authored
    ia64 and ppc64 had hugetlb_free_pgtables functions which were no longer being
    called, and it wasn't obvious what to do about them.
    The ppc64 case turns out to be easy: the associated tables are noted elsewhere
    and freed later, safe to either skip its hugetlb areas or go through the
    motions of freeing nothing.  Since ia64 does need a special case, restore to
    ppc64 the special case of skipping them.
    The ia64 hugetlb case has been broken since pgd_addr_end went in, though it
    probably appeared to work okay if you just had one such area; in fact it's
    been broken much longer if you consider a long munmap spanning from another
    region into the hugetlb region.
    In the ia64 hugetlb region, more virtual address bits are available than in
    the other regions, yet the page tables are structured the same way: the page
    at the bottom is larger.  Here we need to scale down each addr before passing
    it to the standard free_pgd_range.  Was about to write a hugely_scaled_down
    macro, but found htlbpage_to_page already exists for just this purpose.  Fixed
    off-by-one in ia64 is_hugepage_only_range.
    Uninline free_pgd_range to make it available to ia64.  Make sure the
    vma-gathering loop in free_pgtables cannot join a hugepage_only_range to any
    other (safe to join huges?  probably but don't bother).
    Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
hugetlb.h 4.31 KB