Linux-libre 4.5-gnu

1 files changed, 59 insertions, 24 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 87a177917..9a3f6b90e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -489,14 +489,33 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 	struct page *page;
 	struct queue_pages *qp = walk->private;
 	unsigned long flags = qp->flags;
-	int nid;
+	int nid, ret;
 	pte_t *pte;
 	spinlock_t *ptl;
 
-	split_huge_page_pmd(vma, addr, pmd);
-	if (pmd_trans_unstable(pmd))
-		return 0;
+	if (pmd_trans_huge(*pmd)) {
+		ptl = pmd_lock(walk->mm, pmd);
+		if (pmd_trans_huge(*pmd)) {
+			page = pmd_page(*pmd);
+			if (is_huge_zero_page(page)) {
+				spin_unlock(ptl);
+				split_huge_pmd(vma, pmd, addr);
+			} else {
+				get_page(page);
+				spin_unlock(ptl);
+				lock_page(page);
+				ret = split_huge_page(page);
+				unlock_page(page);
+				put_page(page);
+				if (ret)
+					return 0;
+			}
+		} else {
+			spin_unlock(ptl);
+		}
+	}
 
+retry:
 	pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
 	for (; addr != end; pte++, addr += PAGE_SIZE) {
 		if (!pte_present(*pte))
@@ -513,9 +532,23 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 		nid = page_to_nid(page);
 		if (node_isset(nid, *qp->nmask) == !!(flags & MPOL_MF_INVERT))
 			continue;
+		if (PageTransCompound(page) && PageAnon(page)) {
+			get_page(page);
+			pte_unmap_unlock(pte, ptl);
+			lock_page(page);
+			ret = split_huge_page(page);
+			unlock_page(page);
+			put_page(page);
+			/* Failed to split -- skip. */
+			if (ret) {
+				pte = pte_offset_map_lock(walk->mm, pmd,
+						addr, &ptl);
+				continue;
+			}
+			goto retry;
+		}
 
-		if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
-			migrate_page_add(page, qp->pagelist, flags);
+		migrate_page_add(page, qp->pagelist, flags);
 	}
 	pte_unmap_unlock(pte - 1, ptl);
 	cond_resched();
@@ -591,7 +624,7 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
 	unsigned long endvma = vma->vm_end;
 	unsigned long flags = qp->flags;
 
-	if (vma->vm_flags & VM_PFNMAP)
+	if (!vma_migratable(vma))
 		return 1;
 
 	if (endvma > end)
@@ -615,10 +648,8 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
 		return 1;
 	}
 
-	if ((flags & MPOL_MF_STRICT) ||
-	    ((flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) &&
-	     vma_migratable(vma)))
-		/* queue pages from current vma */
+	/* queue pages from current vma */
+	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
 		return 0;
 	return 1;
 }
@@ -2142,12 +2173,14 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
  *
  * Remember policies even when nobody has shared memory mapped.
  * The policies are kept in Red-Black tree linked from the inode.
- * They are protected by the sp->lock spinlock, which should be held
+ * They are protected by the sp->lock rwlock, which should be held
  * for any accesses to the tree.
  */
 
-/* lookup first element intersecting start-end */
-/* Caller holds sp->lock */
+/*
+ * lookup first element intersecting start-end.  Caller holds sp->lock for
+ * reading or for writing
+ */
 static struct sp_node *
 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
 {
@@ -2178,8 +2211,10 @@ sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
 	return rb_entry(n, struct sp_node, nd);
 }
 
-/* Insert a new shared policy into the list. */
-/* Caller holds sp->lock */
+/*
+ * Insert a new shared policy into the list.  Caller holds sp->lock for
+ * writing.
+ */
 static void sp_insert(struct shared_policy *sp, struct sp_node *new)
 {
 	struct rb_node **p = &sp->root.rb_node;
@@ -2211,13 +2246,13 @@ mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 
 	if (!sp->root.rb_node)
 		return NULL;
-	spin_lock(&sp->lock);
+	read_lock(&sp->lock);
 	sn = sp_lookup(sp, idx, idx+1);
 	if (sn) {
 		mpol_get(sn->policy);
 		pol = sn->policy;
 	}
-	spin_unlock(&sp->lock);
+	read_unlock(&sp->lock);
 	return pol;
 }
 
@@ -2360,7 +2395,7 @@ static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
 	int ret = 0;
 
 restart:
-	spin_lock(&sp->lock);
+	write_lock(&sp->lock);
 	n = sp_lookup(sp, start, end);
 	/* Take care of old policies in the same range. */
 	while (n && n->start < end) {
@@ -2393,7 +2428,7 @@ restart:
 	}
 	if (new)
 		sp_insert(sp, new);
-	spin_unlock(&sp->lock);
+	write_unlock(&sp->lock);
 	ret = 0;
 
 err_out:
@@ -2405,7 +2440,7 @@ err_out:
 	return ret;
 
 alloc_new:
-	spin_unlock(&sp->lock);
+	write_unlock(&sp->lock);
 	ret = -ENOMEM;
 	n_new = kmem_cache_alloc(sn_cache, GFP_KERNEL);
 	if (!n_new)
@@ -2431,7 +2466,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 	int ret;
 
 	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
-	spin_lock_init(&sp->lock);
+	rwlock_init(&sp->lock);
 
 	if (mpol) {
 		struct vm_area_struct pvma;
@@ -2497,14 +2532,14 @@ void mpol_free_shared_policy(struct shared_policy *p)
 
 	if (!p->root.rb_node)
 		return;
-	spin_lock(&p->lock);
+	write_lock(&p->lock);
 	next = rb_first(&p->root);
 	while (next) {
 		n = rb_entry(next, struct sp_node, nd);
 		next = rb_next(&n->nd);
 		sp_delete(p, n);
 	}
-	spin_unlock(&p->lock);
+	write_unlock(&p->lock);
 }
 
 #ifdef CONFIG_NUMA_BALANCING