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