For PAGE_ALLOC_COSTLY_ORDER allocations, MIN_COMPACT_COSTLY_PRIORITY is
minimum (highest priority). Other places in the compaction code key off
of MIN_COMPACT_PRIORITY. Costly order allocations will never get to
MIN_COMPACT_PRIORITY. Therefore, some conditions will never be met for
costly order allocations.
This was observed when hugetlb allocations could stall for minutes or
hours when should_compact_retry() would return true more often then it
should. Specifically, this was in the case where compact_result was
COMPACT_DEFERRED and COMPACT_PARTIAL_SKIPPED and no progress was being
made.
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
---
mm/compaction.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 952dc2fb24e5..325b746068d1 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2294,9 +2294,15 @@ static enum compact_result compact_zone_order(struct zone *zone, int order,
.alloc_flags = alloc_flags,
.classzone_idx = classzone_idx,
.direct_compaction = true,
- .whole_zone = (prio == MIN_COMPACT_PRIORITY),
- .ignore_skip_hint = (prio == MIN_COMPACT_PRIORITY),
- .ignore_block_suitable = (prio == MIN_COMPACT_PRIORITY)
+ .whole_zone = ((order > PAGE_ALLOC_COSTLY_ORDER) ?
+ (prio == MIN_COMPACT_COSTLY_PRIORITY) :
+ (prio == MIN_COMPACT_PRIORITY)),
+ .ignore_skip_hint = ((order > PAGE_ALLOC_COSTLY_ORDER) ?
+ (prio == MIN_COMPACT_COSTLY_PRIORITY) :
+ (prio == MIN_COMPACT_PRIORITY)),
+ .ignore_block_suitable = ((order > PAGE_ALLOC_COSTLY_ORDER) ?
+ (prio == MIN_COMPACT_COSTLY_PRIORITY) :
+ (prio == MIN_COMPACT_PRIORITY))
};
struct capture_control capc = {
.cc = &cc,
@@ -2338,6 +2344,7 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
int may_perform_io = gfp_mask & __GFP_IO;
struct zoneref *z;
struct zone *zone;
+ int min_priority;
enum compact_result rc = COMPACT_SKIPPED;
/*
@@ -2350,12 +2357,13 @@ enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
trace_mm_compaction_try_to_compact_pages(order, gfp_mask, prio);
/* Compact each zone in the list */
+ min_priority = (order > PAGE_ALLOC_COSTLY_ORDER) ?
+ MIN_COMPACT_COSTLY_PRIORITY : MIN_COMPACT_PRIORITY;
for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
ac->nodemask) {
enum compact_result status;
- if (prio > MIN_COMPACT_PRIORITY
- && compaction_deferred(zone, order)) {
+ if (prio > min_priority && compaction_deferred(zone, order)) {
rc = max_t(enum compact_result, COMPACT_DEFERRED, rc);
continue;
}
--
2.20.1
