diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 36d9896fbc1eb0d12e60682f15e96648c13ebf98..f4aac87adcc3555014f6215d6599b604c70388e6 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -972,12 +972,16 @@ static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, * @zonelist - The zonelist to search for a suitable zone * @highest_zoneidx - The zone index of the highest zone to return * @nodes - An optional nodemask to filter the zonelist with - * @zone - The first suitable zone found is returned via this parameter + * @return - Zoneref pointer for the first suitable zone found (see below) * * This function returns the first zone at or below a given zone index that is * within the allowed nodemask. The zoneref returned is a cursor that can be * used to iterate the zonelist with next_zones_zonelist by advancing it by * one before calling. + * + * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is + * never NULL). This may happen either genuinely, or due to concurrent nodemask + * update due to cpuset modification. */ static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, enum zone_type highest_zoneidx, diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 41d5e2e2d8ce8c0272e0e7beb52d6f82e9ddfb27..85cf0f715eb0a327d9f6a527f464570e2ac704dd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3784,7 +3784,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, */ ac.preferred_zoneref = first_zones_zonelist(ac.zonelist, ac.high_zoneidx, ac.nodemask); - if (!ac.preferred_zoneref) { + if (!ac.preferred_zoneref->zone) { page = NULL; goto no_zone; }