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authorVlastimil Babka <vbabka@suse.cz>2016-07-28 15:49:28 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-28 16:07:41 -0700
commita5508cd83f10f663e05d212cb81f600a3af46e40 (patch)
treeb52a09bd0be8e756a48b6673c7746b3b0e1b6726 /include/linux
parent2516035499b9555f6acd373c9f12e44bcb50dbec (diff)
mm, compaction: introduce direct compaction priority
In the context of direct compaction, for some types of allocations we would like the compaction to either succeed or definitely fail while trying as hard as possible. Current async/sync_light migration mode is insufficient, as there are heuristics such as caching scanner positions, marking pageblocks as unsuitable or deferring compaction for a zone. At least the final compaction attempt should be able to override these heuristics. To communicate how hard compaction should try, we replace migration mode with a new enum compact_priority and change the relevant function signatures. In compact_zone_order() where struct compact_control is constructed, the priority is mapped to suitable control flags. This patch itself has no functional change, as the current priority levels are mapped back to the same migration modes as before. Expanding them will be done next. Note that !CONFIG_COMPACTION variant of try_to_compact_pages() is removed, as the only caller exists under CONFIG_COMPACTION. Link: http://lkml.kernel.org/r/20160721073614.24395-8-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/compaction.h22
1 files changed, 13 insertions, 9 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 1a02dab16646..0980a6ce4436 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -1,6 +1,18 @@
#ifndef _LINUX_COMPACTION_H
#define _LINUX_COMPACTION_H
+/*
+ * Determines how hard direct compaction should try to succeed.
+ * Lower value means higher priority, analogically to reclaim priority.
+ */
+enum compact_priority {
+ COMPACT_PRIO_SYNC_LIGHT,
+ MIN_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT,
+ DEF_COMPACT_PRIORITY = COMPACT_PRIO_SYNC_LIGHT,
+ COMPACT_PRIO_ASYNC,
+ INIT_COMPACT_PRIORITY = COMPACT_PRIO_ASYNC
+};
+
/* Return values for compact_zone() and try_to_compact_pages() */
/* When adding new states, please adjust include/trace/events/compaction.h */
enum compact_result {
@@ -66,7 +78,7 @@ 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 migrate_mode mode, int *contended);
+ enum compact_priority prio, int *contended);
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,
@@ -151,14 +163,6 @@ extern void kcompactd_stop(int nid);
extern void wakeup_kcompactd(pg_data_t *pgdat, int order, int classzone_idx);
#else
-static inline enum compact_result try_to_compact_pages(gfp_t gfp_mask,
- unsigned int order, int alloc_flags,
- const struct alloc_context *ac,
- enum migrate_mode mode, int *contended)
-{
- return COMPACT_CONTINUE;
-}
-
static inline void compact_pgdat(pg_data_t *pgdat, int order)
{
}