From 3bf5ee95648c694bac4d13529563c230cd4fe5f2 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 19 Apr 2005 13:29:16 -0700 Subject: [PATCH] freepgt: hugetlb_free_pgd_range 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: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-ppc64/pgtable.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'include/asm-ppc64/pgtable.h') diff --git a/include/asm-ppc64/pgtable.h b/include/asm-ppc64/pgtable.h index 4c4824653e80..33b90e2aa47d 100644 --- a/include/asm-ppc64/pgtable.h +++ b/include/asm-ppc64/pgtable.h @@ -500,9 +500,15 @@ extern pgd_t ioremap_dir[1024]; extern void paging_init(void); -struct mmu_gather; -void hugetlb_free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *prev, - unsigned long start, unsigned long end); +/* + * Because the huge pgtables are only 2 level, they can take + * at most around 4M, much less than one hugepage which the + * process is presumably entitled to use. So we don't bother + * freeing up the pagetables on unmap, and wait until + * destroy_context() to clean up the lot. + */ +#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) \ + do { } while (0) /* * This gets called at the end of handling a page fault, when -- cgit v1.2.2