126 	NUMA_INTERLEAVE_HIT,	/* interleaver preferred this zone */
679  * zone lock contention and keep cache-hot pages reusing.
768 	 *    faulted, they come from the right zone right away. However, it is
772 	 *    to a different zone. When migration fails - pinning fails.
793 	 *    on different platforms may end up in a movable zone. ZERO_PAGE(0)
796 	 *    memory to the MOVABLE zone, the vmemmap pages are also placed in
797 	 *    such zone. Such pages cannot be really moved around as they are
819 struct zone {  struct
822 	/* zone watermarks, access with *_wmark_pages(zone) macros */
831 	 * wasting several GB of ram we must reserve some of the lower zone  argument
865 	 * spanned_pages is the total pages spanned by the zone, including  argument
869 	 * present_pages is physical pages existing within the zone, which
873 	 * present_early_pages is present pages existing within the zone
894 	 * It is a seqlock because it has to be read outside of zone->lock,
898 	 * The span_seq lock is declared along with zone->lock because it is
899 	 * frequently read in proximity to zone->lock.  It's good to
922 	 * of pageblock. Protected by zone->lock.  argument
945 	/* zone flags, see below */  argument
990 	/* Zone statistics */
1007 	ZONE_BOOSTED_WATERMARK,		/* zone recently boosted watermarks.  argument
1010 	ZONE_RECLAIM_ACTIVE,		/* kswapd may be scanning the zone. */
1011 	ZONE_BELOW_HIGH,		/* zone is below high watermark. */
1014 static inline unsigned long zone_managed_pages(struct zone *zone)  in zone_managed_pages()  argument
1016 	return (unsigned long)atomic_long_read(&zone->managed_pages);  in zone_managed_pages()
1019 static inline unsigned long zone_cma_pages(struct zone *zone)  in zone_cma_pages()  argument
1022 	return zone->cma_pages;  in zone_cma_pages()
1028 static inline unsigned long zone_end_pfn(const struct zone *zone)  in zone_end_pfn()  argument
1030 	return zone->zone_start_pfn + zone->spanned_pages;  in zone_end_pfn()
1033 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)  in zone_spans_pfn()  argument
1035 	return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);  in zone_spans_pfn()
1038 static inline bool zone_is_initialized(struct zone *zone)  in zone_is_initialized()  argument
1040 	return zone->initialized;  in zone_is_initialized()
1043 static inline bool zone_is_empty(struct zone *zone)  in zone_is_empty()  argument
1045 	return zone->spanned_pages == 0;  in zone_is_empty()
1050  * The zone field is never updated after free_area_init_core()
1054 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1074 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1112  * Consecutive zone device pages should not be merged into the same sgl
1116  * both pages are not zone device pages or both pages are zone device pages
1129 extern void memmap_init_zone_device(struct zone *, unsigned long,
1161  * intersection with the given zone
1163 static inline bool zone_intersects(struct zone *zone,  in zone_intersects()  argument
1166 	if (zone_is_empty(zone))  in zone_intersects()
1168 	if (start_pfn >= zone_end_pfn(zone) ||  in zone_intersects()
1169 	    start_pfn + nr_pages <= zone->zone_start_pfn)  in zone_intersects()
1198  * This struct contains information about a zone in a zonelist. It is stored
1202 	struct zone *zone;	/* Pointer to actual zone */  member
1203 	int zone_idx;		/* zone_idx(zoneref->zone) */
1212  * To speed the reading of the zonelist, the zonerefs contain the zone index
1216  * zonelist_zone()	- Return the struct zone * for an entry in _zonerefs
1217  * zonelist_zone_idx()	- Return the index of the zone for an entry
1270  * per-zone basis.
1278 	struct zone node_zones[MAX_NR_ZONES];
1305 	 * Nests above zone->lock and zone->span_seqlock
1428 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
1430 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
1433 bool zone_watermark_ok(struct zone *z, unsigned int order,
1436 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
1447 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
1468  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
1470 #define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)  argument
1473 static inline bool zone_is_zone_device(struct zone *zone)  in zone_is_zone_device()  argument
1475 	return zone_idx(zone) == ZONE_DEVICE;  in zone_is_zone_device()
1478 static inline bool zone_is_zone_device(struct zone *zone)  in zone_is_zone_device()  argument
1485  * Returns true if a zone has pages managed by the buddy allocator.
1487  * populated_zone(). If the whole zone is reserved then we can easily
1490 static inline bool managed_zone(struct zone *zone)  in managed_zone()  argument
1492 	return zone_managed_pages(zone);  in managed_zone()
1495 /* Returns true if a zone has memory */
1496 static inline bool populated_zone(struct zone *zone)  in populated_zone()  argument
1498 	return zone->present_pages;  in populated_zone()
1502 static inline int zone_to_nid(struct zone *zone)  in zone_to_nid()  argument
1504 	return zone->node;  in zone_to_nid()
1507 static inline void zone_set_nid(struct zone *zone, int nid)  in zone_set_nid()  argument
1509 	zone->node = nid;  in zone_set_nid()
1512 static inline int zone_to_nid(struct zone *zone)  in zone_to_nid()  argument
1517 static inline void zone_set_nid(struct zone *zone, int nid) {}  in zone_set_nid()  argument
1533  * is_highmem - helper function to quickly check if a struct zone is a
1534  *              highmem zone or not.  This is an attempt to keep references
1536  * @zone: pointer to struct zone variable
1537  * Return: 1 for a highmem zone, 0 otherwise
1539 static inline int is_highmem(struct zone *zone)  in is_highmem()  argument
1541 	return is_highmem_idx(zone_idx(zone));  in is_highmem()
1570 extern struct zone *next_zone(struct zone *zone);
1582  * @zone: pointer to struct zone variable
1584  * The user only needs to declare the zone variable, for_each_zone
1587 #define for_each_zone(zone)			        \  argument
1588 	for (zone = (first_online_pgdat())->node_zones; \
1589 	     zone;					\
1590 	     zone = next_zone(zone))
1592 #define for_each_populated_zone(zone)		        \  argument
1593 	for (zone = (first_online_pgdat())->node_zones; \
1594 	     zone;					\
1595 	     zone = next_zone(zone))			\
1596 		if (!populated_zone(zone))		\
1600 static inline struct zone *zonelist_zone(struct zoneref *zoneref)  in zonelist_zone()
1602 	return zoneref->zone;  in zonelist_zone()
1612 	return zone_to_nid(zoneref->zone);  in zonelist_node_idx()
1620 …* next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodem…
1622  * @highest_zoneidx: The zone index of the highest zone to return
1625  * This function returns the next zone at or below a given zone index that is
1627  * search. The zoneref returned is a cursor that represents the current zone
1631  * Return: the next zone at or below highest_zoneidx within the allowed
1644 …* first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nod…
1645  * @zonelist: The zonelist to search for a suitable zone
1646  * @highest_zoneidx: The zone index of the highest zone to return
1649  * This function returns the first zone at or below a given zone index that is
1654  * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1658  * Return: Zoneref pointer for the first suitable zone found
1669 …elper macro to iterate over valid zones in a zonelist at or below a given zone index and within a …
1670  * @zone: The current zone in the iterator
1673  * @highidx: The zone index of the highest zone to return
1676  * This iterator iterates though all zones at or below a given zone index and
1679 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \  argument
1680 	for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z);	\
1681 		zone;							\
1683 			zone = zonelist_zone(z))
1685 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \  argument
1686 	for (zone = z->zone;	\
1687 		zone;							\
1689 			zone = zonelist_zone(z))
1693 …ne_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1694  * @zone: The current zone in the iterator
1697  * @highidx: The zone index of the highest zone to return
1699  * This iterator iterates though all zones at or below a given zone index.
1701 #define for_each_zone_zonelist(zone, z, zlist, highidx) \  argument
1702 	for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1717 	 * at least one zone that can satisfy kernel allocations.  in movable_only_nodes()
1722 	return (!z->zone) ? true : false;  in movable_only_nodes()
1788 	/* See declaration of similar field in struct zone */