diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2016-12-12 16:44:32 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 18:55:08 -0800 |
| commit | 953c66c2b22a304dbc3c3d7fc8e8c25cd97a03d8 (patch) | |
| tree | c851d72f1be182bc4ae4857ff720e34835e68371 /mm/khugepaged.c | |
| parent | 1dd38b6c27d59414e89c08dd1ae9677a8e12cbc4 (diff) | |
| download | lwn-953c66c2b22a304dbc3c3d7fc8e8c25cd97a03d8.tar.gz lwn-953c66c2b22a304dbc3c3d7fc8e8c25cd97a03d8.zip | |
mm: THP page cache support for ppc64
Add arch specific callback in the generic THP page cache code that will
deposit and withdarw preallocated page table. Archs like ppc64 use this
preallocated table to store the hash pte slot information.
Testing:
kernel build of the patch series on tmpfs mounted with option huge=always
The related thp stat:
thp_fault_alloc 72939
thp_fault_fallback 60547
thp_collapse_alloc 603
thp_collapse_alloc_failed 0
thp_file_alloc 253763
thp_file_mapped 4251
thp_split_page 51518
thp_split_page_failed 1
thp_deferred_split_page 73566
thp_split_pmd 665
thp_zero_page_alloc 3
thp_zero_page_alloc_failed 0
[akpm@linux-foundation.org: remove unneeded parentheses, per Kirill]
Link: http://lkml.kernel.org/r/20161113150025.17942-2-aneesh.kumar@linux.vnet.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 7a50c726c5ae..09460955e818 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -1242,6 +1242,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) struct vm_area_struct *vma; unsigned long addr; pmd_t *pmd, _pmd; + bool deposited = false; i_mmap_lock_write(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { @@ -1266,10 +1267,26 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) spinlock_t *ptl = pmd_lock(vma->vm_mm, pmd); /* assume page table is clear */ _pmd = pmdp_collapse_flush(vma, addr, pmd); + /* + * now deposit the pgtable for arch that need it + * otherwise free it. + */ + if (arch_needs_pgtable_deposit()) { + /* + * The deposit should be visibile only after + * collapse is seen by others. + */ + smp_wmb(); + pgtable_trans_huge_deposit(vma->vm_mm, pmd, + pmd_pgtable(_pmd)); + deposited = true; + } spin_unlock(ptl); up_write(&vma->vm_mm->mmap_sem); - atomic_long_dec(&vma->vm_mm->nr_ptes); - pte_free(vma->vm_mm, pmd_pgtable(_pmd)); + if (!deposited) { + atomic_long_dec(&vma->vm_mm->nr_ptes); + pte_free(vma->vm_mm, pmd_pgtable(_pmd)); + } } } i_mmap_unlock_write(mapping); |