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| author | Kirill A. Shutemov | 2016-01-16 01:52:35 +0100 |
|---|---|---|
| committer | Linus Torvalds | 2016-01-16 02:56:32 +0100 |
| commit | 7479df6da9506a624ae214588269ed42221494f9 (patch) | |
| tree | e8bfc07724037bf238aa0d9d0caf6344fdfc1de5 /mm/huge_memory.c | |
| parent | mm: handle PTE-mapped tail pages in gerneric fast gup implementaiton (diff) | |
| download | kernel-qcow2-linux-7479df6da9506a624ae214588269ed42221494f9.tar.gz kernel-qcow2-linux-7479df6da9506a624ae214588269ed42221494f9.tar.xz kernel-qcow2-linux-7479df6da9506a624ae214588269ed42221494f9.zip | |
thp, mlock: do not allow huge pages in mlocked area
With new refcounting THP can belong to several VMAs. This makes tricky
to track THP pages, when they partially mlocked. It can lead to leaking
mlocked pages to non-VM_LOCKED vmas and other problems.
With this patch we will split all pages on mlock and avoid
fault-in/collapse new THP in VM_LOCKED vmas.
I've tried alternative approach: do not mark THP pages mlocked and keep
them on normal LRUs. This way vmscan could try to split huge pages on
memory pressure and free up subpages which doesn't belong to VM_LOCKED
vmas. But this is user-visible change: we screw up Mlocked accouting
reported in meminfo, so I had to leave this approach aside.
We can bring something better later, but this should be good enough for
now.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Steve Capper <steve.capper@linaro.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
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/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index e45918d058b9..b3cc9f27a0ee 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -842,6 +842,8 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, if (haddr < vma->vm_start || haddr + HPAGE_PMD_SIZE > vma->vm_end) return VM_FAULT_FALLBACK; + if (vma->vm_flags & VM_LOCKED) + return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; if (unlikely(khugepaged_enter(vma, vma->vm_flags))) @@ -2555,7 +2557,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma) if ((!(vma->vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || (vma->vm_flags & VM_NOHUGEPAGE)) return false; - + if (vma->vm_flags & VM_LOCKED) + return false; if (!vma->anon_vma || vma->vm_ops) return false; if (is_vma_temporary_stack(vma)) |