Skip to content
Snippets Groups Projects
mmzone.c 2.36 KiB
Newer Older
  • Learn to ignore specific revisions
  • Kenneth Johansson's avatar
    Kenneth Johansson committed
    /*
     * 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 (likely(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;
    }
    
    #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
    bool memmap_valid_within(unsigned long pfn,
    					struct page *page, struct zone *zone)
    {
    	if (page_to_pfn(page) != pfn)
    		return false;
    
    	if (page_zone(page) != zone)
    		return false;
    
    	return true;
    }
    #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
    
    void lruvec_init(struct lruvec *lruvec)
    {
    	enum lru_list lru;
    
    	memset(lruvec, 0, sizeof(struct lruvec));
    
    	for_each_lru(lru)
    		INIT_LIST_HEAD(&lruvec->lists[lru]);
    }
    
    #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;
    
    	do {
    		old_flags = flags = page->flags;
    		last_cpupid = page_cpupid_last(page);
    
    		flags &= ~(LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT);
    		flags |= (cpupid & LAST_CPUPID_MASK) << LAST_CPUPID_PGSHIFT;
    	} while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags));
    
    	return last_cpupid;
    }
    #endif