mm/mempolicy: support MPOL_MF_STRICT for huge page mapping

[uclinux-h8/linux.git] / mm / mempolicy.c

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 977c641..b190cd4 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -557,9 +557,10 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
                               unsigned long addr, unsigned long end,
                               struct mm_walk *walk)
 {
+       int ret = 0;
 #ifdef CONFIG_HUGETLB_PAGE
        struct queue_pages *qp = walk->private;
-       unsigned long flags = qp->flags;
+       unsigned long flags = (qp->flags & MPOL_MF_VALID);
        struct page *page;
        spinlock_t *ptl;
        pte_t entry;
@@ -571,16 +572,44 @@ static int queue_pages_hugetlb(pte_t *pte, unsigned long hmask,
        page = pte_page(entry);
        if (!queue_pages_required(page, qp))
                goto unlock;
+
+       if (flags == MPOL_MF_STRICT) {
+               /*
+                * STRICT alone means only detecting misplaced page and no
+                * need to further check other vma.
+                */
+               ret = -EIO;
+               goto unlock;
+       }
+
+       if (!vma_migratable(walk->vma)) {
+               /*
+                * Must be STRICT with MOVE*, otherwise .test_walk() have
+                * stopped walking current vma.
+                * Detecting misplaced page but allow migrating pages which
+                * have been queued.
+                */
+               ret = 1;
+               goto unlock;
+       }
+
        /* With MPOL_MF_MOVE, we migrate only unshared hugepage. */
        if (flags & (MPOL_MF_MOVE_ALL) ||
-           (flags & MPOL_MF_MOVE && page_mapcount(page) == 1))
-               isolate_huge_page(page, qp->pagelist);
+           (flags & MPOL_MF_MOVE && page_mapcount(page) == 1)) {
+               if (!isolate_huge_page(page, qp->pagelist) &&
+                       (flags & MPOL_MF_STRICT))
+                       /*
+                        * Failed to isolate page but allow migrating pages
+                        * which have been queued.
+                        */
+                       ret = 1;
+       }
 unlock:
        spin_unlock(ptl);
 #else
        BUG();
 #endif
-       return 0;
+       return ret;
 }
 
 #ifdef CONFIG_NUMA_BALANCING