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-rw-r--r--mm/migrate.c15
1 files changed, 12 insertions, 3 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 1379e1912772..959c99cff814 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -74,13 +74,22 @@ int isolate_movable_page(struct page *page, isolate_mode_t mode)
if (unlikely(!get_page_unless_zero(page)))
goto out;
+ if (unlikely(PageSlab(page)))
+ goto out_putpage;
+ /* Pairs with smp_wmb() in slab freeing, e.g. SLUB's __free_slab() */
+ smp_rmb();
/*
- * Check PageMovable before holding a PG_lock because page's owner
- * assumes anybody doesn't touch PG_lock of newly allocated page
- * so unconditionally grabbing the lock ruins page's owner side.
+ * Check movable flag before taking the page lock because
+ * we use non-atomic bitops on newly allocated page flags so
+ * unconditionally grabbing the lock ruins page's owner side.
*/
if (unlikely(!__PageMovable(page)))
goto out_putpage;
+ /* Pairs with smp_wmb() in slab allocation, e.g. SLUB's alloc_slab_page() */
+ smp_rmb();
+ if (unlikely(PageSlab(page)))
+ goto out_putpage;
+
/*
* As movable pages are not isolated from LRU lists, concurrent
* compaction threads can race against page migration functions