1 files changed, 28 insertions, 3 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index d76e8eb342d0..a67c8f1828ac 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1597,6 +1597,10 @@ void mpol_free_shared_policy(struct shared_policy *p)
 /* assumes fs == KERNEL_DS */
 void __init numa_policy_init(void)
 {
+        nodemask_t interleave_nodes;
+        unsigned long largest = 0;
+        int nid, prefer = 0;
+
         policy_cache = kmem_cache_create("numa_policy",
                                          sizeof(struct mempolicy),
                                          0, SLAB_PANIC, NULL, NULL);
@@ -1605,10 +1609,31 @@ void __init numa_policy_init(void)
                                      sizeof(struct sp_node),
                                      0, SLAB_PANIC, NULL, NULL);
 
-        /* Set interleaving policy for system init. This way not all
-           the data structures allocated at system boot end up in node zero. */
+        /*
+         * Set interleaving policy for system init. Interleaving is only
+         * enabled across suitably sized nodes (default is >= 16MB), or
+         * fall back to the largest node if they're all smaller.
+         */
+        nodes_clear(interleave_nodes);
+        for_each_online_node(nid) {
+                unsigned long total_pages = node_present_pages(nid);
+
+                /* Preserve the largest node */
+                if (largest < total_pages) {
+                        largest = total_pages;
+                        prefer = nid;
+                }
+
+                /* Interleave this node? */
+                if ((total_pages << PAGE_SHIFT) >= (16 << 20))
+                        node_set(nid, interleave_nodes);
+        }
+
+        /* All too small, use the largest */
+        if (unlikely(nodes_empty(interleave_nodes)))
+                node_set(prefer, interleave_nodes);
 
-        if (do_set_mempolicy(MPOL_INTERLEAVE, &node_online_map))
+        if (do_set_mempolicy(MPOL_INTERLEAVE, &interleave_nodes))
                 printk("numa_policy_init: interleaving failed\n");
 }