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4468b8f1e2
Andrew Morton pointed out that page_xchg_last_nid() and reset_page_last_nid() were "getting nuttily large" and asked that it be investigated. reset_page_last_nid() is on the page free path and it would be unfortunate to make that path more expensive than it needs to be. Due to the internal use of page_xchg_last_nid() it is already too expensive but fortunately, it should also be impossible for the page->flags to be updated in parallel when we call reset_page_last_nid(). Instead of unlining the function, it uses a simplier implementation that assumes no parallel updates and should now be sufficiently short for inlining. page_xchg_last_nid() is called in paths that are already quite expensive (splitting huge page, fault handling, migration) and it is reasonable to uninline. There was not really a good place to place the function but mm/mmzone.c was the closest fit IMO. This patch saved 128 bytes of text in the vmlinux file for the kernel configuration I used for testing automatic NUMA balancing. Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
117 lines
2.4 KiB
C
117 lines
2.4 KiB
C
/*
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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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struct zone **zone)
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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 (likely(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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*zone = zonelist_zone(z);
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return z;
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}
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#ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
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int memmap_valid_within(unsigned long pfn,
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struct page *page, struct zone *zone)
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{
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if (page_to_pfn(page) != pfn)
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return 0;
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if (page_zone(page) != zone)
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return 0;
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return 1;
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}
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#endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
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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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for_each_lru(lru)
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INIT_LIST_HEAD(&lruvec->lists[lru]);
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}
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#if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_NID_NOT_IN_PAGE_FLAGS)
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int page_xchg_last_nid(struct page *page, int nid)
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{
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unsigned long old_flags, flags;
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int last_nid;
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do {
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old_flags = flags = page->flags;
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last_nid = page_last_nid(page);
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flags &= ~(LAST_NID_MASK << LAST_NID_PGSHIFT);
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flags |= (nid & LAST_NID_MASK) << LAST_NID_PGSHIFT;
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} while (unlikely(cmpxchg(&page->flags, old_flags, flags) != old_flags));
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return last_nid;
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}
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#endif
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