When increasing the compaction priority, also reset retries. Otherwise we can
consume all retries on the lower priorities. Also pull the retries increment
into should_compact_retry() so it counts only the rounds where we actually
rely on it.
Suggested-by: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
---
Please squash into
mm-compaction-more-reliably-increase-direct-compaction-priority.patch
mm/page_alloc.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5155485057cb..0fd29731ab35 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3162,7 +3162,7 @@ static inline bool
should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
enum compact_result compact_result,
enum compact_priority *compact_priority,
- int compaction_retries)
+ int *compaction_retries)
{
int max_retries = MAX_COMPACT_RETRIES;
int min_priority;
@@ -3170,6 +3170,9 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
if (!order)
return false;
+ if (compaction_made_progress(compact_result))
+ (*compaction_retries)++;
+
/*
* compaction considers all the zone as desperately out of memory
* so it doesn't really make much sense to retry except when the
@@ -3197,18 +3200,19 @@ should_compact_retry(struct alloc_context *ac, int order, int alloc_flags,
*/
if (order > PAGE_ALLOC_COSTLY_ORDER)
max_retries /= 4;
- if (compaction_retries <= max_retries)
+ if (*compaction_retries <= max_retries)
return true;
/*
- * Make sure there is at least one attempt at the highest priority
- * if we exhausted all retries at the lower priorities
+ * Make sure there are attempts at the highest priority if we exhausted
+ * all retries or failed at the lower priorities.
*/
check_priority:
min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
if (*compact_priority > min_priority) {
(*compact_priority)--;
+ *compaction_retries = 0;
return true;
}
return false;
@@ -3227,7 +3231,7 @@ static inline bool
should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_flags,
enum compact_result compact_result,
enum compact_priority *compact_priority,
- int compaction_retries)
+ int *compaction_retries)
{
struct zone *zone;
struct zoneref *z;
@@ -3635,9 +3639,6 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
if (page)
goto got_pg;
- if (order && compaction_made_progress(compact_result))
- compaction_retries++;
-
/* Do not loop if specifically requested */
if (gfp_mask & __GFP_NORETRY)
goto nopage;
@@ -3672,7 +3673,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
if (did_some_progress > 0 &&
should_compact_retry(ac, order, alloc_flags,
compact_result, &compact_priority,
- compaction_retries))
+ &compaction_retries))
goto retry;
/* Reclaim has failed us, start killing things */
--
2.10.0
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