Commit 4355c018 authored Mar 15, 2016 by Liang Chen Committed by Linus Torvalds Mar 15, 2016

mm/mempolicy.c: skip VM_HUGETLB and VM_MIXEDMAP VMA for lazy mbind



VM_HUGETLB and VM_MIXEDMAP vma needs to be excluded to avoid compound
pages being marked for migration and unexpected COWs when handling
hugetlb fault.

Thanks to Naoya Horiguchi for reminding me on these checks.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Signed-off-by: Gavin Guo <gavin.guo@canonical.com>
Suggested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: SeongJae Park <sj38.park@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0b94f175

mm/mempolicy.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -643,7 +643,9 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,

		if (flags & MPOL_MF_LAZY) {
		/* Similar to task_numa_work, skip inaccessible VMAs */
		if (vma->vm_flags & (VM_READ \| VM_EXEC \| VM_WRITE))
		if (!is_vm_hugetlb_page(vma) &&
		(vma->vm_flags & (VM_READ \| VM_EXEC \| VM_WRITE)) &&
		!(vma->vm_flags & VM_MIXEDMAP))
		change_prot_numa(vma, start, endvma);
		return 1;
		}