diff options
Diffstat (limited to 'include/linux/compaction.h')
| -rw-r--r-- | include/linux/compaction.h | 40 |
1 files changed, 30 insertions, 10 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h index d4e106b5dc27..0d8415820fc3 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -6,8 +6,10 @@ * Lower value means higher priority, analogically to reclaim priority. */ enum compact_priority { + COMPACT_PRIO_SYNC_FULL, + MIN_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_FULL, COMPACT_PRIO_SYNC_LIGHT, - MIN_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT, + MIN_COMPACT_COSTLY_PRIORITY = COMPACT_PRIO_SYNC_LIGHT, DEF_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT, COMPACT_PRIO_ASYNC, INIT_COMPACT_PRIORITY = COMPACT_PRIO_ASYNC @@ -49,14 +51,37 @@ enum compact_result { COMPACT_CONTENDED, /* - * direct compaction partially compacted a zone and there might be - * suitable pages + * direct compaction terminated after concluding that the allocation + * should now succeed */ - COMPACT_PARTIAL, + COMPACT_SUCCESS, }; struct alloc_context; /* in mm/internal.h */ +/* + * Number of free order-0 pages that should be available above given watermark + * to make sure compaction has reasonable chance of not running out of free + * pages that it needs to isolate as migration target during its work. + */ +static inline unsigned long compact_gap(unsigned int order) +{ + /* + * Although all the isolations for migration are temporary, compaction + * free scanner may have up to 1 << order pages on its list and then + * try to split an (order - 1) free page. At that point, a gap of + * 1 << order might not be enough, so it's safer to require twice that + * amount. Note that the number of pages on the list is also + * effectively limited by COMPACT_CLUSTER_MAX, as that's the maximum + * that the migrate scanner can have isolated on migrate list, and free + * scanner is only invoked when the number of isolated free pages is + * lower than that. But it's not worth to complicate the formula here + * as a bigger gap for higher orders than strictly necessary can also + * improve chances of compaction success. + */ + return 2UL << order; +} + #ifdef CONFIG_COMPACTION extern int sysctl_compact_memory; extern int sysctl_compaction_handler(struct ctl_table *table, int write, @@ -70,7 +95,6 @@ extern int fragmentation_index(struct zone *zone, unsigned int order); extern enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order, unsigned int alloc_flags, const struct alloc_context *ac, enum compact_priority prio); -extern void compact_pgdat(pg_data_t *pgdat, int order); extern void reset_isolation_suitable(pg_data_t *pgdat); extern enum compact_result compaction_suitable(struct zone *zone, int order, unsigned int alloc_flags, int classzone_idx); @@ -89,7 +113,7 @@ static inline bool compaction_made_progress(enum compact_result result) * that the compaction successfully isolated and migrated some * pageblocks. */ - if (result == COMPACT_PARTIAL) + if (result == COMPACT_SUCCESS) return true; return false; @@ -154,10 +178,6 @@ extern void kcompactd_stop(int nid); extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx); #else -static inline void compact_pgdat(pg_data_t *pgdat, int order) -{ -} - static inline void reset_isolation_suitable(pg_data_t *pgdat) { } |