This BUG_ON() was triggered when called from try_to_unmap_cluster() which didn't lock the page. And it's safe to mlock_vma_page() without PageLocked, so this patch fix this issue by removing that BUG_ON() simply. [ 253.869145] kernel BUG at mm/mlock.c:82! [ 253.869549] invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 253.870098] Dumping ftrace buffer: [ 253.870098] (ftrace buffer empty) [ 253.870098] Modules linked in: [ 253.870098] CPU: 10 PID: 9162 Comm: trinity-child75 Tainted: G W 3.13.0-rc4-next-20131216-sasha-00011-g5f105ec-dirty #4137 [ 253.873310] task: ffff8800c98cb000 ti: ffff8804d34e8000 task.ti: ffff8804d34e8000 [ 253.873310] RIP: 0010:[<ffffffff81281f28>] [<ffffffff81281f28>] mlock_vma_page+0x18/0xc0 [ 253.873310] RSP: 0000:ffff8804d34e99e8 EFLAGS: 00010246 [ 253.873310] RAX: 006fffff8038002c RBX: ffffea00474944c0 RCX: ffff880807636000 [ 253.873310] RDX: ffffea0000000000 RSI: 00007f17a9bca000 RDI: ffffea00474944c0 [ 253.873310] RBP: ffff8804d34e99f8 R08: ffff880807020000 R09: 0000000000000000 [ 253.873310] R10: 0000000000000001 R11: 0000000000002000 R12: 00007f17a9bca000 [ 253.873310] R13: ffffea00474944c0 R14: 00007f17a9be0000 R15: ffff880807020000 [ 253.873310] FS: 00007f17aa31a700(0000) GS:ffff8801c9c00000(0000) knlGS:0000000000000000 [ 253.873310] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 253.873310] CR2: 00007f17a94fa000 CR3: 00000004d3b02000 CR4: 00000000000006e0 [ 253.873310] DR0: 00007f17a74ca000 DR1: 0000000000000000 DR2: 0000000000000000 [ 253.873310] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 [ 253.873310] Stack: [ 253.873310] 0000000b3de28067 ffff880b3de28e50 ffff8804d34e9aa8 ffffffff8128bc31 [ 253.873310] 0000000000000301 ffffea0011850220 ffff8809a4039000 ffffea0011850238 [ 253.873310] ffff8804d34e9aa8 ffff880807636060 0000000000000001 ffff880807636348 [ 253.873310] Call Trace: [ 253.873310] [<ffffffff8128bc31>] try_to_unmap_cluster+0x1c1/0x340 [ 253.873310] [<ffffffff8128c60a>] try_to_unmap_file+0x20a/0x2e0 [ 253.873310] [<ffffffff8128c7b3>] try_to_unmap+0x73/0x90 [ 253.873310] [<ffffffff812b526d>] __unmap_and_move+0x18d/0x250 [ 253.873310] [<ffffffff812b53e9>] unmap_and_move+0xb9/0x180 [ 253.873310] [<ffffffff812b559b>] migrate_pages+0xeb/0x2f0 [ 253.873310] [<ffffffff812a0660>] ? queue_pages_pte_range+0x1a0/0x1a0 [ 253.873310] [<ffffffff812a193c>] migrate_to_node+0x9c/0xc0 [ 253.873310] [<ffffffff812a30b8>] do_migrate_pages+0x1b8/0x240 [ 253.873310] [<ffffffff812a3456>] SYSC_migrate_pages+0x316/0x380 [ 253.873310] [<ffffffff812a31ec>] ? SYSC_migrate_pages+0xac/0x380 [ 253.873310] [<ffffffff811763c6>] ? vtime_account_user+0x96/0xb0 [ 253.873310] [<ffffffff812a34ce>] SyS_migrate_pages+0xe/0x10 [ 253.873310] [<ffffffff843c4990>] tracesys+0xdd/0xe2 [ 253.873310] Code: 0f 1f 00 65 48 ff 04 25 10 25 1d 00 48 83 c4 08 5b c9 c3 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 48 8b 07 48 89 fb a8 01 75 10 <0f> 0b 66 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 f0 0f ba 2f 15 [ 253.873310] RIP [<ffffffff81281f28>] mlock_vma_page+0x18/0xc0 [ 253.873310] RSP <ffff8804d34e99e8> [ 253.904194] ---[ end trace be59c4a7f8edab3f ]--- Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Signed-off-by: Bob Liu <bob.liu@xxxxxxxxxx> --- mm/mlock.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/mlock.c b/mm/mlock.c index d480cd6..5488d44 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -79,8 +79,6 @@ void clear_page_mlock(struct page *page) */ void mlock_vma_page(struct page *page) { - BUG_ON(!PageLocked(page)); - if (!TestSetPageMlocked(page)) { mod_zone_page_state(page_zone(page), NR_MLOCK, hpage_nr_pages(page)); -- 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>