It's not guaranteed that highest will be above the min_pfn. If highest is
below the min_pfn, migrate_pfn and free_pfn can meet prematurely and lead
to some useless work. Make sure highest is above min_pfn to avoid making
a futile effort.
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
mm/compaction.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index 609a76d7e051..65970107b789 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1532,7 +1532,7 @@ fast_isolate_freepages(struct compact_control *cc)
* not found, be pessimistic for direct compaction
* and use the min mark.
*/
- if (highest) {
+ if (highest >= min_pfn) {
page = pfn_to_page(highest);
cc->free_pfn = highest;
} else {
--
2.23.0
