I'm still seeing this one from time to time, though it takes me quite a while to hit it, despite my attempts at trying to narrow down the set of syscalls that cause it. kernel BUG at mm/filemap.c:202! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 3 PID: 3013 Comm: trinity-c361 Not tainted 3.15.0-rc8+ #225 task: ffff88006c610000 ti: ffff880055960000 task.ti: ffff880055960000 RIP: 0010:[<ffffffffac158e28>] [<ffffffffac158e28>] __delete_from_page_cache+0x318/0x360 RSP: 0018:ffff880055963b90 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffff880146f68388 RDX: 000000000000022a RSI: ffffffffaca8db38 RDI: ffffffffaca62b17 RBP: ffff880055963be0 R08: 0000000000000002 R09: ffff88000613d530 R10: ffff880055963ba8 R11: ffff880007f49a40 R12: ffffea0006795880 R13: ffff880143232ad0 R14: 0000000000000000 R15: ffff880143232ad8 FS: 00007f1e40673700(0000) GS:ffff88024d180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1e404e6000 CR3: 00000000603eb000 CR4: 00000000001407e0 DR0: 0000000001bb1000 DR1: 0000000002537000 DR2: 00000000016a5000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Stack: ffff880143232ae8 0000000000000000 ffff88000613d530 ffff88000613d568 0000000008828259 ffffea0006795880 ffff880143232ae8 0000000000000000 0000000000000002 0000000000000002 ffff880055963c08 ffffffffac158eae Call Trace: [<ffffffffac158eae>] delete_from_page_cache+0x3e/0x70 [<ffffffffac16921b>] truncate_inode_page+0x5b/0x90 [<ffffffffac174493>] shmem_undo_range+0x363/0x790 [<ffffffffac1748d4>] shmem_truncate_range+0x14/0x30 [<ffffffffac174bcf>] shmem_fallocate+0x9f/0x340 [<ffffffffac324d40>] ? timerqueue_add+0x60/0xb0 [<ffffffffac1c5ff6>] do_fallocate+0x116/0x1a0 [<ffffffffac182260>] SyS_madvise+0x3c0/0x870 [<ffffffffac346b33>] ? __this_cpu_preempt_check+0x13/0x20 [<ffffffffac74c41f>] tracesys+0xdd/0xe2 Code: ff ff 01 41 f6 c6 01 48 8b 45 c8 75 16 4c 89 30 e9 70 fe ff ff 66 0f 1f 44 00 00 0f 0b 66 0f 1f 44 00 00 0f 0b 66 0f 1f 44 00 00 <0f> 0b 66 0f 1f 44 00 00 41 54 9d e8 78 9e fd ff e9 8c fe ff ff RIP [<ffffffffac158e28>] __delete_from_page_cache+0x318/0x360 There was also another variant of the same BUG with a slighty different stack trace. kernel BUG at mm/filemap.c:202! invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 2 PID: 6928 Comm: trinity-c45 Not tainted 3.15.0-rc5+ #208 task: ffff88023669d0a0 ti: ffff880186146000 task.ti: ffff880186146000 RIP: 0010:[<ffffffff8415ba05>] [<ffffffff8415ba05>] __delete_from_page_cache+0x315/0x320 RSP: 0018:ffff880186147b18 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000002 RDX: 000000000000012a RSI: ffffffff84a9a83c RDI: ffffffff84a6e0c0 RBP: ffff880186147b68 R08: 0000000000000002 R09: ffff88002669e668 R10: ffff880186147b30 R11: 0000000000000000 R12: ffffea0008b067c0 R13: ffff880025355670 R14: 0000000000000000 R15: ffff880025355678 FS: 00007fc10026f740(0000) GS:ffff880244400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002ab350f5c004 CR3: 000000018566c000 CR4: 00000000001407e0 DR0: 0000000001989000 DR1: 0000000000944000 DR2: 0000000002494000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Stack: ffff880025355688 ffff8800253556a0 ffff88002669e668 ffff88002669e6a0 000000008ea099ef ffffea0008b067c0 ffff880025355688 0000000000000000 0000000000000000 0000000000000002 ffff880186147b90 ffffffff8415ba4d Call Trace: [<ffffffff8415ba4d>] delete_from_page_cache+0x3d/0x70 [<ffffffff8416b0ab>] truncate_inode_page+0x5b/0x90 [<ffffffff84175f0b>] shmem_undo_range+0x30b/0x780 [<ffffffff84176394>] shmem_truncate_range+0x14/0x30 [<ffffffff8417647d>] shmem_evict_inode+0xcd/0x150 [<ffffffff841e4b17>] evict+0xa7/0x170 [<ffffffff841e5435>] iput+0xf5/0x180 [<ffffffff841df8a0>] dentry_kill+0x260/0x2d0 [<ffffffff841df97c>] dput+0x6c/0x110 [<ffffffff841c92a9>] __fput+0x189/0x200 [<ffffffff841c936e>] ____fput+0xe/0x10 [<ffffffff84090484>] task_work_run+0xb4/0xe0 [<ffffffff8406ee42>] do_exit+0x302/0xb80 [<ffffffff84349e13>] ? __this_cpu_preempt_check+0x13/0x20 [<ffffffff8407073c>] do_group_exit+0x4c/0xc0 [<ffffffff840707c4>] SyS_exit_group+0x14/0x20 [<ffffffff8475bf64>] tracesys+0xdd/0xe2 Code: 4c 89 30 e9 80 fe ff ff 48 8b 75 c0 4c 89 ff e8 82 8f 1c 00 84 c0 0f 85 6c fe ff ff e9 4f fe ff ff 0f 1f 44 00 00 e8 ae 95 5e 00 <0f> 0b e8 04 1c f1 ff 0f 0b 66 90 0f 1f 44 00 00 55 48 89 e5 41 -- 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>