diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 15 |
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 |