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authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>2016-07-26 15:25:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-26 16:19:19 -0700
commitb5072380eb619786990cd9eab3ade05d09ccd89e (patch)
treeb5b8d219600e15da7247eacad7788c241b5f19e1 /mm/huge_memory.c
parent95ecedcd6abbb05d8177331e2fa697888dcd634b (diff)
thp: support file pages in zap_huge_pmd()
split_huge_pmd() for file mappings (and DAX too) is implemented by just clearing pmd entry as we can re-fill this area from page cache on pte level later. This means we don't need deposit page tables when file THP is mapped. Therefore we shouldn't try to withdraw a page table on zap_huge_pmd() file THP PMD. Link: http://lkml.kernel.org/r/1466021202-61880-14-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r--mm/huge_memory.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 5bc058ad12c2..d8ccd245947d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1689,10 +1689,16 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
struct page *page = pmd_page(orig_pmd);
page_remove_rmap(page, true);
VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
- add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
VM_BUG_ON_PAGE(!PageHead(page), page);
- pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
- atomic_long_dec(&tlb->mm->nr_ptes);
+ if (PageAnon(page)) {
+ pgtable_t pgtable;
+ pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
+ pte_free(tlb->mm, pgtable);
+ atomic_long_dec(&tlb->mm->nr_ptes);
+ add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
+ } else {
+ add_mm_counter(tlb->mm, MM_FILEPAGES, -HPAGE_PMD_NR);
+ }
spin_unlock(ptl);
tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE);
}