diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2012-12-12 13:51:02 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-12-12 17:38:31 -0800 |
| commit | 80371957f09814d25c38733d2d08de47f59a13c2 (patch) | |
| tree | 2ebdedfa3a10af22941e44729f1c4c2623e8da74 /mm | |
| parent | c5a647d09fe9fc3e0241c89845cf8e6220b916f5 (diff) | |
| download | lwn-80371957f09814d25c38733d2d08de47f59a13c2.tar.gz lwn-80371957f09814d25c38733d2d08de47f59a13c2.zip | |
thp: setup huge zero page on non-write page fault
All code paths seems covered. Now we can map huge zero page on read page
fault.
We setup it in do_huge_pmd_anonymous_page() if area around fault address
is suitable for THP and we've got read page fault.
If we fail to setup huge zero page (ENOMEM) we fallback to
handle_pte_fault() as we normally do in THP.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ea0e23fd6967..e1b6f4e13b91 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -733,6 +733,16 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma))) return VM_FAULT_OOM; + if (!(flags & FAULT_FLAG_WRITE)) { + pgtable_t pgtable; + pgtable = pte_alloc_one(mm, haddr); + if (unlikely(!pgtable)) + return VM_FAULT_OOM; + spin_lock(&mm->page_table_lock); + set_huge_zero_page(pgtable, mm, vma, haddr, pmd); + spin_unlock(&mm->page_table_lock); + return 0; + } page = alloc_hugepage_vma(transparent_hugepage_defrag(vma), vma, haddr, numa_node_id(), 0); if (unlikely(!page)) { |