mm, compaction: rename COMPACT_PARTIAL to COMPACT_SUCCESS
COMPACT_PARTIAL has historically meant that compaction returned after
doing some work without fully compacting a zone. It however didn't
distinguish if compaction terminated because it succeeded in creating
the requested high-order page. This has changed recently and now we
only return COMPACT_PARTIAL when compaction thinks it succeeded, or the
high-order watermark check in compaction_suitable() passes and no
compaction needs to be done.
So at this point we can make the return value clearer by renaming it to
COMPACT_SUCCESS. The next patch will remove some redundant tests for
success where compaction just returned COMPACT_SUCCESS.
Link: http://lkml.kernel.org/r/20160810091226.6709-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index 8e32778..335eeee 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1329,13 +1329,13 @@
/* Job done if page is free of the right migratetype */
if (!list_empty(&area->free_list[migratetype]))
- return COMPACT_PARTIAL;
+ return COMPACT_SUCCESS;
#ifdef CONFIG_CMA
/* MIGRATE_MOVABLE can fallback on MIGRATE_CMA */
if (migratetype == MIGRATE_MOVABLE &&
!list_empty(&area->free_list[MIGRATE_CMA]))
- return COMPACT_PARTIAL;
+ return COMPACT_SUCCESS;
#endif
/*
* Job done if allocation would steal freepages from
@@ -1343,7 +1343,7 @@
*/
if (find_suitable_fallback(area, order, migratetype,
true, &can_steal) != -1)
- return COMPACT_PARTIAL;
+ return COMPACT_SUCCESS;
}
return COMPACT_NO_SUITABLE_PAGE;
@@ -1367,7 +1367,7 @@
* compaction_suitable: Is this suitable to run compaction on this zone now?
* Returns
* COMPACT_SKIPPED - If there are too few free pages for compaction
- * COMPACT_PARTIAL - If the allocation would succeed without compaction
+ * COMPACT_SUCCESS - If the allocation would succeed without compaction
* COMPACT_CONTINUE - If compaction should run now
*/
static enum compact_result __compaction_suitable(struct zone *zone, int order,
@@ -1388,7 +1388,7 @@
*/
if (zone_watermark_ok(zone, order, watermark, classzone_idx,
alloc_flags))
- return COMPACT_PARTIAL;
+ return COMPACT_SUCCESS;
/*
* Watermarks for order-0 must be met for compaction. Note the 2UL.
@@ -1477,7 +1477,7 @@
ret = compaction_suitable(zone, cc->order, cc->alloc_flags,
cc->classzone_idx);
/* Compaction is likely to fail */
- if (ret == COMPACT_PARTIAL || ret == COMPACT_SKIPPED)
+ if (ret == COMPACT_SUCCESS || ret == COMPACT_SKIPPED)
return ret;
/* huh, compaction_suitable is returning something unexpected */