From: Zi Yan <ziy@xxxxxxxxxx>
In isolate_migratepages_block(), a !PageLRU tail page can be encountered
when the page is larger than a pageblock. Use compound head page for the
checks inside and skip the entire compound page when isolation succeeds.
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
mm/compaction.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index b4e94cda3019..ad9053fbbe06 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -979,19 +979,23 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* Skip any other type of page
*/
if (!PageLRU(page)) {
+ struct page *head = compound_head(page);
/*
* __PageMovable can return false positive so we need
* to verify it under page_lock.
*/
- if (unlikely(__PageMovable(page)) &&
- !PageIsolated(page)) {
+ if (unlikely(__PageMovable(head)) &&
+ !PageIsolated(head)) {
if (locked) {
unlock_page_lruvec_irqrestore(locked, flags);
locked = NULL;
}
- if (!isolate_movable_page(page, isolate_mode))
+ if (!isolate_movable_page(head, isolate_mode)) {
+ low_pfn += (1 << compound_order(head)) - 1 - (page - head);
+ page = head;
goto isolate_success;
+ }
}
goto isolate_fail;
--
2.34.1
