148 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef _LINUX_COMPACTION_H
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| #define _LINUX_COMPACTION_H
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| 
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| /*
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|  * Determines how hard direct compaction should try to succeed.
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|  * Lower value means higher priority, analogically to reclaim priority.
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|  */
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| enum compact_priority {
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| 	COMPACT_PRIO_SYNC_FULL,
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| 	MIN_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_FULL,
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| 	COMPACT_PRIO_SYNC_LIGHT,
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| 	MIN_COMPACT_COSTLY_PRIORITY = COMPACT_PRIO_SYNC_LIGHT,
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| 	DEF_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT,
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| 	COMPACT_PRIO_ASYNC,
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| 	INIT_COMPACT_PRIORITY = COMPACT_PRIO_ASYNC
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| };
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| 
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| /* Return values for compact_zone() and try_to_compact_pages() */
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| /* When adding new states, please adjust include/trace/events/compaction.h */
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| enum compact_result {
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| 	/* For more detailed tracepoint output - internal to compaction */
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| 	COMPACT_NOT_SUITABLE_ZONE,
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| 	/*
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| 	 * compaction didn't start as it was not possible or direct reclaim
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| 	 * was more suitable
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| 	 */
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| 	COMPACT_SKIPPED,
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| 	/* compaction didn't start as it was deferred due to past failures */
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| 	COMPACT_DEFERRED,
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| 
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| 	/* For more detailed tracepoint output - internal to compaction */
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| 	COMPACT_NO_SUITABLE_PAGE,
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| 	/* compaction should continue to another pageblock */
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| 	COMPACT_CONTINUE,
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| 
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| 	/*
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| 	 * The full zone was compacted scanned but wasn't successful to compact
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| 	 * suitable pages.
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| 	 */
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| 	COMPACT_COMPLETE,
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| 	/*
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| 	 * direct compaction has scanned part of the zone but wasn't successful
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| 	 * to compact suitable pages.
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| 	 */
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| 	COMPACT_PARTIAL_SKIPPED,
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| 
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| 	/* compaction terminated prematurely due to lock contentions */
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| 	COMPACT_CONTENDED,
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| 
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| 	/*
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| 	 * direct compaction terminated after concluding that the allocation
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| 	 * should now succeed
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| 	 */
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| 	COMPACT_SUCCESS,
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| };
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| 
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| struct alloc_context; /* in mm/internal.h */
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| 
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| /*
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|  * Number of free order-0 pages that should be available above given watermark
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|  * to make sure compaction has reasonable chance of not running out of free
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|  * pages that it needs to isolate as migration target during its work.
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|  */
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| static inline unsigned long compact_gap(unsigned int order)
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| {
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| 	/*
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| 	 * Although all the isolations for migration are temporary, compaction
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| 	 * free scanner may have up to 1 << order pages on its list and then
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| 	 * try to split an (order - 1) free page. At that point, a gap of
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| 	 * 1 << order might not be enough, so it's safer to require twice that
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| 	 * amount. Note that the number of pages on the list is also
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| 	 * effectively limited by COMPACT_CLUSTER_MAX, as that's the maximum
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| 	 * that the migrate scanner can have isolated on migrate list, and free
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| 	 * scanner is only invoked when the number of isolated free pages is
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| 	 * lower than that. But it's not worth to complicate the formula here
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| 	 * as a bigger gap for higher orders than strictly necessary can also
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| 	 * improve chances of compaction success.
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| 	 */
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| 	return 2UL << order;
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| }
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| 
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| #ifdef CONFIG_COMPACTION
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| 
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| extern unsigned int extfrag_for_order(struct zone *zone, unsigned int order);
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| extern int fragmentation_index(struct zone *zone, unsigned int order);
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| extern enum compact_result try_to_compact_pages(gfp_t gfp_mask,
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| 		unsigned int order, unsigned int alloc_flags,
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| 		const struct alloc_context *ac, enum compact_priority prio,
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| 		struct page **page);
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| extern void reset_isolation_suitable(pg_data_t *pgdat);
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| extern bool compaction_suitable(struct zone *zone, int order,
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| 					       int highest_zoneidx);
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| 
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| extern void compaction_defer_reset(struct zone *zone, int order,
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| 				bool alloc_success);
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| 
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| bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
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| 					int alloc_flags);
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| 
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| extern void __meminit kcompactd_run(int nid);
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| extern void __meminit kcompactd_stop(int nid);
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| extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int highest_zoneidx);
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| 
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| #else
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| static inline void reset_isolation_suitable(pg_data_t *pgdat)
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| {
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| }
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| 
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| static inline bool compaction_suitable(struct zone *zone, int order,
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| 						      int highest_zoneidx)
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| {
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| 	return false;
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| }
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| 
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| static inline void kcompactd_run(int nid)
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| {
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| }
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| static inline void kcompactd_stop(int nid)
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| {
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| }
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| 
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| static inline void wakeup_kcompactd(pg_data_t *pgdat,
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| 				int order, int highest_zoneidx)
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| {
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| }
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| 
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| #endif /* CONFIG_COMPACTION */
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| 
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| struct node;
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| #if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
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| extern int compaction_register_node(struct node *node);
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| extern void compaction_unregister_node(struct node *node);
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| 
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| #else
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| 
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| static inline int compaction_register_node(struct node *node)
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| {
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| 	return 0;
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| }
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| 
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| static inline void compaction_unregister_node(struct node *node)
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| {
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| }
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| #endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
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| 
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| #endif /* _LINUX_COMPACTION_H */
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