[PATCH] freepgt: hugetlb area is clean
Hugh Dickins [Tue, 19 Apr 2005 20:29:18 +0000 (13:29 -0700)]
Once we're strict about clearing away page tables, hugetlb_prefault can assume
there are no page tables left within its range.  Since the other arches
continue if !pte_none here, let i386 do the same.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/mm/hugetlbpage.c
arch/ppc64/mm/hugetlbpage.c

index a8c4514..171fc92 100644 (file)
@@ -249,15 +249,8 @@ int hugetlb_prefault(struct address_space *mapping, struct vm_area_struct *vma)
                        goto out;
                }
 
-               if (!pte_none(*pte)) {
-                       pmd_t *pmd = (pmd_t *) pte;
-
-                       page = pmd_page(*pmd);
-                       pmd_clear(pmd);
-                       mm->nr_ptes--;
-                       dec_page_state(nr_page_table_pages);
-                       page_cache_release(page);
-               }
+               if (!pte_none(*pte))
+                       continue;
 
                idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
                        + (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
index 8665bb5..390296e 100644 (file)
@@ -203,8 +203,6 @@ static int prepare_low_seg_for_htlb(struct mm_struct *mm, unsigned long seg)
        unsigned long start = seg << SID_SHIFT;
        unsigned long end = (seg+1) << SID_SHIFT;
        struct vm_area_struct *vma;
-       unsigned long addr;
-       struct mmu_gather *tlb;
 
        BUG_ON(seg >= 16);
 
@@ -213,41 +211,6 @@ static int prepare_low_seg_for_htlb(struct mm_struct *mm, unsigned long seg)
        if (vma && (vma->vm_start < end))
                return -EBUSY;
 
-       /* Clean up any leftover PTE pages in the region */
-       spin_lock(&mm->page_table_lock);
-       tlb = tlb_gather_mmu(mm, 0);
-       for (addr = start; addr < end; addr += PMD_SIZE) {
-               pgd_t *pgd = pgd_offset(mm, addr);
-               pmd_t *pmd;
-               struct page *page;
-               pte_t *pte;
-               int i;
-
-               if (pgd_none(*pgd))
-                       continue;
-               pmd = pmd_offset(pgd, addr);
-               if (!pmd || pmd_none(*pmd))
-                       continue;
-               if (pmd_bad(*pmd)) {
-                       pmd_ERROR(*pmd);
-                       pmd_clear(pmd);
-                       continue;
-               }
-               pte = (pte_t *)pmd_page_kernel(*pmd);
-               /* No VMAs, so there should be no PTEs, check just in case. */
-               for (i = 0; i < PTRS_PER_PTE; i++) {
-                       BUG_ON(!pte_none(*pte));
-                       pte++;
-               }
-               page = pmd_page(*pmd);
-               pmd_clear(pmd);
-               mm->nr_ptes--;
-               dec_page_state(nr_page_table_pages);
-               pte_free_tlb(tlb, page);
-       }
-       tlb_finish_mmu(tlb, start, end);
-       spin_unlock(&mm->page_table_lock);
-
        return 0;
 }