VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page) in lru_cache_add() was triggered during migrate_misplaced_transhuge_page. [ 477.301955] kernel BUG at mm/swap.c:609! [ 477.302564] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 477.303590] Dumping ftrace buffer: [ 477.305022] (ftrace buffer empty) [ 477.305899] Modules linked in: [ 477.306397] CPU: 35 PID: 10092 Comm: trinity-c374 Tainted: G W 3.14.0-rc5-next-20140307-sasha-00010-g1f812cb #142 [ 477.307644] task: ffff8800a7f80000 ti: ffff8800a7f6a000 task.ti: ffff8800a7f6a000 [ 477.309124] RIP: 0010:[<ffffffff8127f311>] [<ffffffff8127f311>] lru_cache_add+0x21/0x60 [ 477.310301] RSP: 0000:ffff8800a7f6bbc8 EFLAGS: 00010292 [ 477.311110] RAX: 000000000000003f RBX: ffffea0013d68000 RCX: 0000000000000006 [ 477.311110] RDX: 0000000000000006 RSI: ffff8800a7f80d60 RDI: 0000000000000282 [ 477.311110] RBP: ffff8800a7f6bbc8 R08: 0000000000000001 R09: 0000000000000001 [ 477.311110] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8800ab9b0c00 [ 477.311110] R13: 0000000002400000 R14: ffff8800ab9b0c00 R15: 0000000000000001 [ 477.311110] FS: 00007ff2c047c700(0000) GS:ffff88042bc00000(0000) knlGS:0000000000000000 [ 477.311110] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 477.311110] CR2: 0000000003788a68 CR3: 00000000a7f68000 CR4: 00000000000006a0 [ 477.311110] DR0: 000000000069b000 DR1: 0000000000000000 DR2: 0000000000000000 [ 477.311110] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 477.311110] Stack: [ 477.311110] ffff8800a7f6bbf8 ffffffff812adaec ffffea0013d68000 ffffea002bdb8000 [ 477.311110] ffffea0013d68000 ffff8800a7f7c090 ffff8800a7f6bca8 ffffffff812db8ec [ 477.311110] 0000000000000001 ffffffff812e1321 ffff8800a7f6bc48 ffffffff811ad632 [ 477.311110] Call Trace: [ 477.311110] [<ffffffff812adaec>] page_add_new_anon_rmap+0x1ec/0x210 [ 477.311110] [<ffffffff812db8ec>] migrate_misplaced_transhuge_page+0x55c/0x830 [ 477.311110] [<ffffffff812e1321>] ? do_huge_pmd_numa_page+0x311/0x460 [ 477.311110] [<ffffffff811ad632>] ? __lock_release+0x1e2/0x200 [ 477.311110] [<ffffffff812e133f>] do_huge_pmd_numa_page+0x32f/0x460 [ 477.311110] [<ffffffff81af6aca>] ? delay_tsc+0xfa/0x120 [ 477.311110] [<ffffffff812a31f4>] __handle_mm_fault+0x244/0x3a0 [ 477.311110] [<ffffffff812e37ed>] ? rcu_read_unlock+0x5d/0x60 [ 477.311110] [<ffffffff812a3463>] handle_mm_fault+0x113/0x1c0 [ 477.311110] [<ffffffff844abd42>] ? __do_page_fault+0x302/0x5d0 [ 477.311110] [<ffffffff844abfd1>] __do_page_fault+0x591/0x5d0 [ 477.311110] [<ffffffff8118ab46>] ? vtime_account_user+0x96/0xb0 [ 477.311110] [<ffffffff844ac492>] ? preempt_count_sub+0xe2/0x120 [ 477.311110] [<ffffffff81269567>] ? context_tracking_user_exit+0x187/0x1d0 [ 477.311110] [<ffffffff844ac0d5>] do_page_fault+0x45/0x70 [ 477.311110] [<ffffffff844ab386>] do_async_page_fault+0x36/0x100 [ 477.311110] [<ffffffff844a7f18>] async_page_fault+0x28/0x30 [ 477.311110] Code: 65 f0 4c 8b 6d f8 c9 c3 66 90 55 48 89 e5 66 66 66 66 90 48 8b 07 a8 40 74 18 48 8b 07 a9 00 00 10 00 74 0e 31 f6 e8 2f 20 ff ff <0f> 0b eb fe 0f 1f 00 48 8b 07 a8 20 74 19 31 f6 e8 1a 20 ff ff [ 477.311110] RIP [<ffffffff8127f311>] lru_cache_add+0x21/0x60 [ 477.311110] RSP <ffff8800a7f6bbc8> The root cause is the checking mlocked_vma_newpage() in page_add_new_anon_rmap() is not enough to decide whether a page is unevictable. migrate_misplaced_transhuge_page(): => migrate_page_copy() => SetPageUnevictable(newpage) => page_add_new_anon_rmap(newpage) => mlocked_vma_newpage(vma, newpage) <--This check is not enough => SetPageActive(newpage) => lru_cache_add(newpage) => VM_BUG_ON_PAGE() >From vmscan.c: * Reasons page might not be evictable: * (1) page's mapping marked unevictable * (2) page is part of an mlocked VMA But page_add_new_anon_rmap() only checks reason (2), we may hit this VM_BUG_ON_PAGE() if PageUnevictable(old_page) was originally set by reason (1). Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx> --- mm/rmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/rmap.c b/mm/rmap.c index 43d429b..39458c5 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1024,7 +1024,7 @@ void page_add_new_anon_rmap(struct page *page, __mod_zone_page_state(page_zone(page), NR_ANON_PAGES, hpage_nr_pages(page)); __page_set_anon_rmap(page, vma, address, 1); - if (!mlocked_vma_newpage(vma, page)) { + if (!mlocked_vma_newpage(vma, page) && !PageUnevictable(page)) { SetPageActive(page); lru_cache_add(page); } else -- 1.7.10.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>