// SPDX-License-Identifier: GPL-2.0 /* * linux/mm/mmzone.c * * management codes for pgdats, zones and page flags */ #include <linux/stddef.h> #include <linux/mm.h> #include <linux/mmzone.h> struct pglist_data *first_online_pgdat(void) { return NODE_DATA(first_online_node); } struct pglist_data *next_online_pgdat(struct pglist_data *pgdat) { int nid = next_online_node(pgdat->node_id); if (nid == MAX_NUMNODES) return NULL; return NODE_DATA(nid); } /* * next_zone - helper magic for for_each_zone() */ struct zone *next_zone(struct zone *zone) { pg_data_t *pgdat = zone->zone_pgdat; if (zone < pgdat->node_zones + MAX_NR_ZONES - 1) zone++; else { pgdat = next_online_pgdat(pgdat); if (pgdat) zone = pgdat->node_zones; else zone = NULL; } return zone; } static inline int zref_in_nodemask(struct zoneref *zref, nodemask_t *nodes) { #ifdef CONFIG_NUMA return node_isset(zonelist_node_idx(zref), *nodes); #else return 1; #endif /* CONFIG_NUMA */ } /* Returns the next zone at or below highest_zoneidx in a zonelist */ struct zoneref *__next_zones_zonelist(struct zoneref *z, enum zone_type highest_zoneidx, nodemask_t *nodes) { /* * Find the next suitable zone to use for the allocation. * Only filter based on nodemask if it's set */ if (unlikely(nodes == NULL)) while (zonelist_zone_idx(z) > highest_zoneidx) z++; else while (zonelist_zone_idx(z) > highest_zoneidx || (z->zone && !zref_in_nodemask(z, nodes))) z++; return z; } void lruvec_init(struct lruvec *lruvec) { enum lru_list lru; memset(lruvec, 0, sizeof(struct lruvec)); spin_lock_init(&lruvec->lru_lock); for_each_lru(lru) INIT_LIST_HEAD(&lruvec->lists[lru]); /* * The "Unevictable LRU" is imaginary: though its size is maintained, * it is never scanned, and unevictable pages are not threaded on it * (so that their lru fields can be reused to hold mlock_count). * Poison its list head, so that any operations on it would crash. */ list_del(&lruvec->lists[LRU_UNEVICTABLE]); } #if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) int page_cpupid_xchg_last(struct page *page, int cpupid) { unsigned long old_flags, flags; int last_cpupid; old_flags = READ_ONCE(page->flags); do { flags = old_flags; last_cpupid = (flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK; flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT); flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT; } while (unlikely(!try_cmpxchg(&page->flags, &old_flags, flags))); return last_cpupid; } #endif