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authorRik van Riel <riel@redhat.com>2012-03-21 16:33:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-21 17:54:56 -0700
commitaff622495c9a0b56148192e53bdec539f5e147f2 (patch)
tree78f6400d8b6bec3279483006a0e9543e47aa833e
parent7be62de99adcab4449d416977b4274985c5fe023 (diff)
downloadop-kernel-dev-aff622495c9a0b56148192e53bdec539f5e147f2.zip
op-kernel-dev-aff622495c9a0b56148192e53bdec539f5e147f2.tar.gz
vmscan: only defer compaction for failed order and higher
Currently a failed order-9 (transparent hugepage) compaction can lead to memory compaction being temporarily disabled for a memory zone. Even if we only need compaction for an order 2 allocation, eg. for jumbo frames networking. The fix is relatively straightforward: keep track of the highest order at which compaction is succeeding, and only defer compaction for orders at which compaction is failing. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/compaction.h14
-rw-r--r--include/linux/mmzone.h1
-rw-r--r--mm/compaction.c12
-rw-r--r--mm/page_alloc.c6
-rw-r--r--mm/vmscan.c2
5 files changed, 27 insertions, 8 deletions
diff --git a/include/linux/compaction.h b/include/linux/compaction.h
index 7a9323a..51a90b7 100644
--- a/include/linux/compaction.h
+++ b/include/linux/compaction.h
@@ -34,20 +34,26 @@ extern unsigned long compaction_suitable(struct zone *zone, int order);
* allocation success. 1 << compact_defer_limit compactions are skipped up
* to a limit of 1 << COMPACT_MAX_DEFER_SHIFT
*/
-static inline void defer_compaction(struct zone *zone)
+static inline void defer_compaction(struct zone *zone, int order)
{
zone->compact_considered = 0;
zone->compact_defer_shift++;
+ if (order < zone->compact_order_failed)
+ zone->compact_order_failed = order;
+
if (zone->compact_defer_shift > COMPACT_MAX_DEFER_SHIFT)
zone->compact_defer_shift = COMPACT_MAX_DEFER_SHIFT;
}
/* Returns true if compaction should be skipped this time */
-static inline bool compaction_deferred(struct zone *zone)
+static inline bool compaction_deferred(struct zone *zone, int order)
{
unsigned long defer_limit = 1UL << zone->compact_defer_shift;
+ if (order < zone->compact_order_failed)
+ return false;
+
/* Avoid possible overflow */
if (++zone->compact_considered > defer_limit)
zone->compact_considered = defer_limit;
@@ -73,11 +79,11 @@ static inline unsigned long compaction_suitable(struct zone *zone, int order)
return COMPACT_SKIPPED;
}
-static inline void defer_compaction(struct zone *zone)
+static inline void defer_compaction(struct zone *zone, int order)
{
}
-static inline bool compaction_deferred(struct zone *zone)
+static inline bool compaction_deferred(struct zone *zone, int order)
{
return 1;
}
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 650ba2f..dff7115 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -365,6 +365,7 @@ struct zone {
*/
unsigned int compact_considered;
unsigned int compact_defer_shift;
+ int compact_order_failed;
#endif
ZONE_PADDING(_pad1_)
diff --git a/mm/compaction.c b/mm/compaction.c
index 36f0f61..c4b344a 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -695,9 +695,19 @@ static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
INIT_LIST_HEAD(&cc->freepages);
INIT_LIST_HEAD(&cc->migratepages);
- if (cc->order < 0 || !compaction_deferred(zone))
+ if (cc->order < 0 || !compaction_deferred(zone, cc->order))
compact_zone(zone, cc);
+ if (cc->order > 0) {
+ int ok = zone_watermark_ok(zone, cc->order,
+ low_wmark_pages(zone), 0, 0);
+ if (ok && cc->order > zone->compact_order_failed)
+ zone->compact_order_failed = cc->order + 1;
+ /* Currently async compaction is never deferred. */
+ else if (!ok && cc->sync)
+ defer_compaction(zone, cc->order);
+ }
+
VM_BUG_ON(!list_empty(&cc->freepages));
VM_BUG_ON(!list_empty(&cc->migratepages));
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a13ded1..572b93e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1990,7 +1990,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
if (!order)
return NULL;
- if (compaction_deferred(preferred_zone)) {
+ if (compaction_deferred(preferred_zone, order)) {
*deferred_compaction = true;
return NULL;
}
@@ -2012,6 +2012,8 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
if (page) {
preferred_zone->compact_considered = 0;
preferred_zone->compact_defer_shift = 0;
+ if (order >= preferred_zone->compact_order_failed)
+ preferred_zone->compact_order_failed = order + 1;
count_vm_event(COMPACTSUCCESS);
return page;
}
@@ -2028,7 +2030,7 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
* defer if the failure was a sync compaction failure.
*/
if (sync_migration)
- defer_compaction(preferred_zone);
+ defer_compaction(preferred_zone, order);
cond_resched();
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b2b4c4a..87e4d6a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2198,7 +2198,7 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc)
* If compaction is deferred, reclaim up to a point where
* compaction will have a chance of success when re-enabled
*/
- if (compaction_deferred(zone))
+ if (compaction_deferred(zone, sc->order))
return watermark_ok;
/* If compaction is not ready to start, keep reclaiming */
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