aboutsummaryrefslogtreecommitdiffstats
path: root/mm
diff options
context:
space:
mode:
Diffstat (limited to 'mm')
-rw-r--r--mm/compaction.c43
-rw-r--r--mm/page_alloc.c4
2 files changed, 42 insertions, 5 deletions
diff --git a/mm/compaction.c b/mm/compaction.c
index 8f211bd2ea0d..546e571e9d60 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1158,6 +1158,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
unsigned long end_pfn = zone_end_pfn(zone);
const int migratetype = gfpflags_to_migratetype(cc->gfp_mask);
const bool sync = cc->mode != MIGRATE_ASYNC;
+ unsigned long last_migrated_pfn = 0;
ret = compaction_suitable(zone, cc->order, cc->alloc_flags,
cc->classzone_idx);
@@ -1203,6 +1204,7 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
while ((ret = compact_finished(zone, cc, migratetype)) ==
COMPACT_CONTINUE) {
int err;
+ unsigned long isolate_start_pfn = cc->migrate_pfn;
switch (isolate_migratepages(zone, cc)) {
case ISOLATE_ABORT:
@@ -1211,7 +1213,12 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
cc->nr_migratepages = 0;
goto out;
case ISOLATE_NONE:
- continue;
+ /*
+ * We haven't isolated and migrated anything, but
+ * there might still be unflushed migrations from
+ * previous cc->order aligned block.
+ */
+ goto check_drain;
case ISOLATE_SUCCESS:
;
}
@@ -1236,6 +1243,40 @@ static int compact_zone(struct zone *zone, struct compact_control *cc)
goto out;
}
}
+
+ /*
+ * Record where we could have freed pages by migration and not
+ * yet flushed them to buddy allocator. We use the pfn that
+ * isolate_migratepages() started from in this loop iteration
+ * - this is the lowest page that could have been isolated and
+ * then freed by migration.
+ */
+ if (!last_migrated_pfn)
+ last_migrated_pfn = isolate_start_pfn;
+
+check_drain:
+ /*
+ * Has the migration scanner moved away from the previous
+ * cc->order aligned block where we migrated from? If yes,
+ * flush the pages that were freed, so that they can merge and
+ * compact_finished() can detect immediately if allocation
+ * would succeed.
+ */
+ if (cc->order > 0 && last_migrated_pfn) {
+ int cpu;
+ unsigned long current_block_start =
+ cc->migrate_pfn & ~((1UL << cc->order) - 1);
+
+ if (last_migrated_pfn < current_block_start) {
+ cpu = get_cpu();
+ lru_add_drain_cpu(cpu);
+ drain_local_pages(zone);
+ put_cpu();
+ /* No more flushing until we migrate again */
+ last_migrated_pfn = 0;
+ }
+ }
+
}
out:
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index edb0ce1e7cf3..7352aa45a335 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2359,10 +2359,6 @@ __alloc_pages_direct_compact(gfp_t gfp_mask, unsigned int order,
*/
count_vm_event(COMPACTSTALL);
- /* Page migration frees to the PCP lists but we want merging */
- drain_pages(get_cpu());
- put_cpu();
-
page = get_page_from_freelist(gfp_mask, nodemask,
order, zonelist, high_zoneidx,
alloc_flags & ~ALLOC_NO_WATERMARKS,

Privacy Policy