118  * cachelines.  There are very few zone structures in the machine, so space
135 	NUMA_INTERLEAVE_HIT,	/* interleaver preferred this zone */
439 	 *    faulted, they come from the right zone right away. However, it is
443 	 *    to a different zone. When migration fails - pinning fails.
464 	 *    on different platforms may end up in a movable zone. ZERO_PAGE(0)
467 	 *    memory to the MOVABLE zone, the vmemmap pages are also placed in
468 	 *    such zone. Such pages cannot be really moved around as they are
490 struct zone {  struct
493 	/* zone watermarks, access with *_wmark_pages(zone) macros */
502 	 * wasting several GB of ram we must reserve some of the lower zone  argument
535 	 * spanned_pages is the total pages spanned by the zone, including  argument
539 	 * present_pages is physical pages existing within the zone, which
543 	 * present_early_pages is present pages existing within the zone
564 	 * It is a seqlock because it has to be read outside of zone->lock,
568 	 * The span_seq lock is declared along with zone->lock because it is
569 	 * frequently read in proximity to zone->lock.  It's good to
592 	 * of pageblock. Protected by zone->lock.  argument
610 	/* zone flags, see below */  argument
655 	/* Zone statistics */
672 	ZONE_BOOSTED_WATERMARK,		/* zone recently boosted watermarks.  argument
675 	ZONE_RECLAIM_ACTIVE,		/* kswapd may be scanning the zone. */
678 static inline unsigned long zone_managed_pages(struct zone *zone)  in zone_managed_pages()  argument
680 	return (unsigned long)atomic_long_read(&zone->managed_pages);  in zone_managed_pages()
683 static inline unsigned long zone_cma_pages(struct zone *zone)  in zone_cma_pages()  argument
686 	return zone->cma_pages;  in zone_cma_pages()
692 static inline unsigned long zone_end_pfn(const struct zone *zone)  in zone_end_pfn()  argument
694 	return zone->zone_start_pfn + zone->spanned_pages;  in zone_end_pfn()
697 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)  in zone_spans_pfn()  argument
699 	return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);  in zone_spans_pfn()
702 static inline bool zone_is_initialized(struct zone *zone)  in zone_is_initialized()  argument
704 	return zone->initialized;  in zone_is_initialized()
707 static inline bool zone_is_empty(struct zone *zone)  in zone_is_empty()  argument
709 	return zone->spanned_pages == 0;  in zone_is_empty()
714  * intersection with the given zone
716 static inline bool zone_intersects(struct zone *zone,  in zone_intersects()  argument
719 	if (zone_is_empty(zone))  in zone_intersects()
721 	if (start_pfn >= zone_end_pfn(zone) ||  in zone_intersects()
722 	    start_pfn + nr_pages <= zone->zone_start_pfn)  in zone_intersects()
751  * This struct contains information about a zone in a zonelist. It is stored
755 	struct zone *zone;	/* Pointer to actual zone */  member
756 	int zone_idx;		/* zone_idx(zoneref->zone) */
765  * To speed the reading of the zonelist, the zonerefs contain the zone index
769  * zonelist_zone()	- Return the struct zone * for an entry in _zonerefs
770  * zonelist_zone_idx()	- Return the index of the zone for an entry
798  * per-zone basis.
806 	struct zone node_zones[MAX_NR_ZONES];
833 	 * Nests above zone->lock and zone->span_seqlock
930 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
932 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
935 bool zone_watermark_ok(struct zone *z, unsigned int order,
938 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
949 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
970  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
972 #define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)  argument
975 static inline bool zone_is_zone_device(struct zone *zone)  in zone_is_zone_device()  argument
977 	return zone_idx(zone) == ZONE_DEVICE;  in zone_is_zone_device()
980 static inline bool zone_is_zone_device(struct zone *zone)  in zone_is_zone_device()  argument
987  * Returns true if a zone has pages managed by the buddy allocator.
989  * populated_zone(). If the whole zone is reserved then we can easily
992 static inline bool managed_zone(struct zone *zone)  in managed_zone()  argument
994 	return zone_managed_pages(zone);  in managed_zone()
997 /* Returns true if a zone has memory */
998 static inline bool populated_zone(struct zone *zone)  in populated_zone()  argument
1000 	return zone->present_pages;  in populated_zone()
1004 static inline int zone_to_nid(struct zone *zone)  in zone_to_nid()  argument
1006 	return zone->node;  in zone_to_nid()
1009 static inline void zone_set_nid(struct zone *zone, int nid)  in zone_set_nid()  argument
1011 	zone->node = nid;  in zone_set_nid()
1014 static inline int zone_to_nid(struct zone *zone)  in zone_to_nid()  argument
1019 static inline void zone_set_nid(struct zone *zone, int nid) {}  in zone_set_nid()  argument
1035  * is_highmem - helper function to quickly check if a struct zone is a
1036  *              highmem zone or not.  This is an attempt to keep references
1038  * @zone: pointer to struct zone variable
1039  * Return: 1 for a highmem zone, 0 otherwise
1041 static inline int is_highmem(struct zone *zone)  in is_highmem()  argument
1044 	return is_highmem_idx(zone_idx(zone));  in is_highmem()
1050 /* These two functions are used to setup the per zone pages min values */
1089 extern struct zone *next_zone(struct zone *zone);
1101  * @zone: pointer to struct zone variable
1103  * The user only needs to declare the zone variable, for_each_zone
1106 #define for_each_zone(zone)			        \  argument
1107 	for (zone = (first_online_pgdat())->node_zones; \
1108 	     zone;					\
1109 	     zone = next_zone(zone))
1111 #define for_each_populated_zone(zone)		        \  argument
1112 	for (zone = (first_online_pgdat())->node_zones; \
1113 	     zone;					\
1114 	     zone = next_zone(zone))			\
1115 		if (!populated_zone(zone))		\
1119 static inline struct zone *zonelist_zone(struct zoneref *zoneref)  in zonelist_zone()
1121 	return zoneref->zone;  in zonelist_zone()
1131 	return zone_to_nid(zoneref->zone);  in zonelist_node_idx()
1139 …* next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodem…
1141  * @highest_zoneidx: The zone index of the highest zone to return
1144  * This function returns the next zone at or below a given zone index that is
1146  * search. The zoneref returned is a cursor that represents the current zone
1150  * Return: the next zone at or below highest_zoneidx within the allowed
1163 …* first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nod…
1164  * @zonelist: The zonelist to search for a suitable zone
1165  * @highest_zoneidx: The zone index of the highest zone to return
1168  * This function returns the first zone at or below a given zone index that is
1173  * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1177  * Return: Zoneref pointer for the first suitable zone found
1188 …elper macro to iterate over valid zones in a zonelist at or below a given zone index and within a …
1189  * @zone: The current zone in the iterator
1192  * @highidx: The zone index of the highest zone to return
1195  * This iterator iterates though all zones at or below a given zone index and
1198 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \  argument
1199 	for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z);	\
1200 		zone;							\
1202 			zone = zonelist_zone(z))
1204 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \  argument
1205 	for (zone = z->zone;	\
1206 		zone;							\
1208 			zone = zonelist_zone(z))
1212 …ne_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1213  * @zone: The current zone in the iterator
1216  * @highidx: The zone index of the highest zone to return
1218  * This iterator iterates though all zones at or below a given zone index.
1220 #define for_each_zone_zonelist(zone, z, zlist, highidx) \  argument
1221 	for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1284 	/* See declaration of similar field in struct zone */