1 files changed, 23 insertions, 10 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 673596ad9c80..40de6854b980 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2380,8 +2380,9 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 {
         enum zone_type high_zoneidx = gfp_zone(gfp_mask);
         struct zone *preferred_zone;
-        struct page *page;
+        struct page *page = NULL;
         int migratetype = allocflags_to_migratetype(gfp_mask);
+        unsigned int cpuset_mems_cookie;
 
         gfp_mask &= gfp_allowed_mask;
 
@@ -2400,15 +2401,15 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
         if (unlikely(!zonelist->_zonerefs->zone))
                 return NULL;
 
-        get_mems_allowed();
+retry_cpuset:
+        cpuset_mems_cookie = get_mems_allowed();
+
         /* The preferred zone is used for statistics later */
         first_zones_zonelist(zonelist, high_zoneidx,
                                 nodemask ? : &cpuset_current_mems_allowed,
                                 &preferred_zone);
-        if (!preferred_zone) {
-                put_mems_allowed();
-                return NULL;
-        }
+        if (!preferred_zone)
+                goto out;
 
         /* First allocation attempt */
         page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
@@ -2418,9 +2419,19 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
                 page = __alloc_pages_slowpath(gfp_mask, order,
                                 zonelist, high_zoneidx, nodemask,
                                 preferred_zone, migratetype);
-        put_mems_allowed();
 
         trace_mm_page_alloc(page, order, gfp_mask, migratetype);
+
+out:
+        /*
+         * When updating a task's mems_allowed, it is possible to race with
+         * parallel threads in such a way that an allocation can fail while
+         * the mask is being updated. If a page allocation is about to fail,
+         * check if the cpuset changed during allocation and if so, retry.
+         */
+        if (unlikely(!put_mems_allowed(cpuset_mems_cookie) && !page))
+                goto retry_cpuset;
+
         return page;
 }
 EXPORT_SYMBOL(__alloc_pages_nodemask);
@@ -2634,13 +2645,15 @@ void si_meminfo_node(struct sysinfo *val, int nid)
 bool skip_free_areas_node(unsigned int flags, int nid)
 {
         bool ret = false;
+        unsigned int cpuset_mems_cookie;
 
         if (!(flags & SHOW_MEM_FILTER_NODES))
                 goto out;
 
-        get_mems_allowed();
-        ret = !node_isset(nid, cpuset_current_mems_allowed);
-        put_mems_allowed();
+        do {
+                cpuset_mems_cookie = get_mems_allowed();
+                ret = !node_isset(nid, cpuset_current_mems_allowed);
+        } while (!put_mems_allowed(cpuset_mems_cookie));
 out:
         return ret;
 }