On Wed, 18 Dec 2013, Sasha Levin wrote: > Hi all, > > As a side note, I seem to be hitting various VM_BUG_ON(!PageLocked(page)) all > over the code, is it > possible that something major broke that's causing this fallout? > > While fuzzing with trinity inside a KVM tools guest running latest -next > kernel, I've stumbled on the following spew. > > [ 588.698828] kernel BUG at mm/rmap.c:1663! > [ 588.699380] invalid opcode: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC > [ 588.700347] Dumping ftrace buffer: > [ 588.701186] (ftrace buffer empty) > [ 588.702062] Modules linked in: > [ 588.702759] CPU: 0 PID: 4647 Comm: kswapd0 Tainted: G D W > 3.13.0-rc4-next-20 > 131218-sasha-00012-g1962367-dirty #4155 > [ 588.704330] task: ffff880062bcb000 ti: ffff880062450000 task.ti: > ffff880062450000 > [ 588.705507] RIP: 0010:[<ffffffff81289c80>] [<ffffffff81289c80>] > rmap_walk+0x10/0x50 > [ 588.706800] RSP: 0018:ffff8800624518d8 EFLAGS: 00010246 > [ 588.707515] RAX: 000fffff80080048 RBX: ffffea00000227c0 RCX: > 0000000000000000 > [ 588.707515] RDX: 0000000000000000 RSI: ffff8800624518e8 RDI: > ffffea00000227c0 > [ 588.707515] RBP: ffff8800624518d8 R08: ffff8800624518e8 R09: > 0000000000000000 > [ 588.707515] R10: 0000000000000000 R11: 0000000000000000 R12: > ffff8800624519d8 > [ 588.707515] R13: 0000000000000000 R14: ffffea00000227e0 R15: > 0000000000000000 > [ 588.707515] FS: 0000000000000000(0000) GS:ffff880065200000(0000) > knlGS:000000000000 > 0000 > [ 588.707515] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 588.707515] CR2: 00007fec40cbe0f8 CR3: 00000000c2382000 CR4: > 00000000000006f0 > [ 588.707515] Stack: > [ 588.707515] ffff880062451958 ffffffff81289f4b ffff880062451918 > ffffffff81289f80 > [ 588.707515] 0000000000000000 0000000000000000 ffffffff8128af60 > 0000000000000000 > [ 588.707515] 0000000000000024 0000000000000000 0000000000000000 > 0000000000000286 > [ 588.707515] Call Trace: > [ 588.707515] [<ffffffff81289f4b>] page_referenced+0xcb/0x100 > [ 588.707515] [<ffffffff81289f80>] ? page_referenced+0x100/0x100 > [ 588.707515] [<ffffffff8128af60>] ? > invalid_page_referenced_vma+0x170/0x170 > [ 588.707515] [<ffffffff81264302>] shrink_active_list+0x212/0x330 > [ 588.707515] [<ffffffff81260e23>] ? inactive_file_is_low+0x33/0x50 > [ 588.707515] [<ffffffff812646f5>] shrink_lruvec+0x2d5/0x300 > [ 588.707515] [<ffffffff812647b6>] shrink_zone+0x96/0x1e0 > [ 588.707515] [<ffffffff81265b06>] kswapd_shrink_zone+0xf6/0x1c0 > [ 588.707515] [<ffffffff81265f43>] balance_pgdat+0x373/0x550 > [ 588.707515] [<ffffffff81266d63>] kswapd+0x2f3/0x350 > [ 588.707515] [<ffffffff81266a70>] ? > perf_trace_mm_vmscan_lru_isolate_template+0x120/ > 0x120 > [ 588.707515] [<ffffffff8115c9c5>] kthread+0x105/0x110 > [ 588.707515] [<ffffffff8115c8c0>] ? set_kthreadd_affinity+0x30/0x30 > [ 588.707515] [<ffffffff843a6a7c>] ret_from_fork+0x7c/0xb0 > [ 588.707515] [<ffffffff8115c8c0>] ? set_kthreadd_affinity+0x30/0x30 > [ 588.707515] Code: c0 48 83 c4 18 89 d0 5b 41 5c 41 5d 41 5e 41 5f c9 c3 66 > 0f 1f 84 > 00 00 00 00 00 55 48 89 e5 66 66 66 66 90 48 8b 07 a8 01 75 10 <0f> 0b 66 0f > 1f 44 00 0 > 0 eb fe 66 0f 1f 44 00 00 f6 47 08 01 74 > [ 588.707515] RIP [<ffffffff81289c80>] rmap_walk+0x10/0x50 > [ 588.707515] RSP <ffff8800624518d8> Yes, I hit that on starting swap load on Monday's mmotm: sighed and moved on. I've not investigated: as you'll have noticed from other unreplied (but not ignored) fallocate mail, I've not had much time to spare. Finger of probable but unsubstantiated blame points to the rmap_walk patches, Joonsoo Cc'ed. Hugh -- 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>