cpuset: mm: reduce large amounts of memory barrier related damage v3

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / slub.c

diff --git a/mm/slub.c b/mm/slub.c
index 4907563..f4a6229 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1581,6 +1581,7 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
        struct zone *zone;
        enum zone_type high_zoneidx = gfp_zone(flags);
        void *object;
+       unsigned int cpuset_mems_cookie;
 
        /*
         * The defrag ratio allows a configuration of the tradeoffs between
@@ -1604,23 +1605,32 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags,
                        get_cycles() % 1024 > s->remote_node_defrag_ratio)
                return NULL;
 
-       get_mems_allowed();
-       zonelist = node_zonelist(slab_node(current->mempolicy), flags);
-       for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
-               struct kmem_cache_node *n;
-
-               n = get_node(s, zone_to_nid(zone));
-
-               if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
-                               n->nr_partial > s->min_partial) {
-                       object = get_partial_node(s, n, c);
-                       if (object) {
-                               put_mems_allowed();
-                               return object;
+       do {
+               cpuset_mems_cookie = get_mems_allowed();
+               zonelist = node_zonelist(slab_node(current->mempolicy), flags);
+               for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+                       struct kmem_cache_node *n;
+
+                       n = get_node(s, zone_to_nid(zone));
+
+                       if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
+                                       n->nr_partial > s->min_partial) {
+                               object = get_partial_node(s, n, c);
+                               if (object) {
+                                       /*
+                                        * Return the object even if
+                                        * put_mems_allowed indicated that
+                                        * the cpuset mems_allowed was
+                                        * updated in parallel. It's a
+                                        * harmless race between the alloc
+                                        * and the cpuset update.
+                                        */
+                                       put_mems_allowed(cpuset_mems_cookie);
+                                       return object;
+                               }
                        }
                }
-       }
-       put_mems_allowed();
+       } while (!put_mems_allowed(cpuset_mems_cookie));
 #endif
        return NULL;
 }