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 <[email protected]> Signed-off-by: Gavin Guo <[email protected]> Suggested-by: Naoya Horiguchi <[email protected]> Acked-by: David Rientjes <[email protected]> Cc: SeongJae Park <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Mel Gorman <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
mrcsosa · Mar 15, 2016 · 4355c01 · 4355c01
1 parent 0b94f17
commit 4355c01
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
@@ -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;
 	}