Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1423387

[PATCHv9-rebased2 13/37] thp: support file pages in zap_huge_pmd()

Show all headers | View raw

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.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 mm/huge_memory.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b24b7993c369..d8fd49073280 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1693,10 +1693,16 @@ 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);
 	}
-- 
2.8.1

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCHv9-rebased2 00/37] THP-enabled tmpfs/shmem using compound pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 05/37] khugepaged: recheck pmd after mmap_sem re-acquired "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
    Re: [PATCHv9-rebased2 05/37] khugepaged: recheck pmd after mmap_sem  re-acquired Ebru Akagunduz <ebru.akagunduz@gmail.com> - 2016-06-16 13:50 +0200
      Re: [PATCHv9-rebased2 05/37] khugepaged: recheck pmd after mmap_sem  re-acquired "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-06-16 14:00 +0200
  [PATCHv9-rebased2 12/37] thp, vmstats: add counters for huge file pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 17/37] thp: prepare change_huge_pmd() for file thp "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 09/37] mm: postpone page table allocation until we have page to map "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 18/37] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 21/37] vmscan: split file huge pages before paging them out "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 13/37] thp: support file pages in zap_huge_pmd() "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 29/37] shmem: add huge pages support "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 06/37] thp, mlock: update unevictable-lru.txt "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 19/37] thp: file pages support for split_huge_page() "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 28/37] shmem: get_unmapped_area align huge page "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 07/37] mm: do not pass mm_struct into handle_mm_fault "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 34/37] khugepaged: add support of collapse for tmpfs/shmem pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 14/37] thp: handle file pages in split_huge_pmd() "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 11/37] mm: introduce do_set_pmd() "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 26/37] mm, rmap: account shmem thp pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 25/37] truncate: handle file thp "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 24/37] filemap: prepare find and delete operations for huge pages "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 22/37] page-flags: relax policy for PG_mappedtodisk and PG_reclaim "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 27/37] shmem: prepare huge= mount option and sysfs knob "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 10/37] rmap: support file thp "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:20 +0200
  [PATCHv9-rebased2 04/37]  mm-thp-make-swapin-readahead-under-down_read-of-mmap_sem-fix-2-fix "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-06-15 22:30 +0200

csiph-web