INFO: task loop0:4304 blocked for more than 120 seconds.
      Not tainted 4.4.138-g226f96b #61
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
loop0           D ffff8801d8c46d40 25536  4304      2 0x00000000
 ffff8801d8c46d40 ffffffff841e9980 ffffffff8122f030 ffff8800b653d0e0
 ffff8801db21f400 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffffffff84417840 ffff8800b653c800 ffff8801d8c47610
Call Trace:
 [<ffffffff838b46ea>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838bfb01>] schedule_timeout+0x481/0x8b0 kernel/time/timer.c:1515
 [<ffffffff838b25aa>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:4941
 [<ffffffff81db234f>] io_schedule include/linux/sched.h:447 [inline]
 [<ffffffff81db234f>] bt_get+0x2af/0x760 block/blk-mq-tag.c:301
 [<ffffffff81db3645>] __blk_mq_get_tag block/blk-mq-tag.c:325 [inline]
 [<ffffffff81db3645>] blk_mq_get_tag+0x1f5/0x360 block/blk-mq-tag.c:353
 [<ffffffff81da3307>] __blk_mq_alloc_request+0x27/0xa40 block/blk-mq.c:215
 [<ffffffff81da94b2>] blk_mq_map_request.isra.42+0x732/0xe00 block/blk-mq.c:1190
 [<ffffffff81dad52d>] blk_sq_make_request+0x1ad/0xe60 block/blk-mq.c:1361
 [<ffffffff81d7f541>] generic_make_request+0x211/0x9b0 block/blk-core.c:2081
 [<ffffffff81d7fdbf>] submit_bio+0xdf/0x3b0 block/blk-core.c:2154
 [<ffffffff815e1aab>] dio_bio_submit fs/direct-io.c:409 [inline]
 [<ffffffff815e1aab>] do_blockdev_direct_IO+0x5aab/0x82f0 fs/direct-io.c:1283
 [<ffffffff815e439e>] __blockdev_direct_IO+0xae/0xe0 fs/direct-io.c:1342
 [<ffffffff815d1182>] blkdev_direct_IO+0xb2/0xe0 fs/block_dev.c:167
 [<ffffffff8142417c>] generic_file_read_iter+0x35c/0x11a0 mm/filemap.c:1799
 [<ffffffff815d3e85>] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1679
 [<ffffffff8251e221>] lo_rw_aio+0x481/0x870 drivers/block/loop.c:506
 [<ffffffff82520477>] lo_rw_simple drivers/block/loop.c:520 [inline]
 [<ffffffff82520477>] do_req_filebacked drivers/block/loop.c:558 [inline]
 [<ffffffff82520477>] loop_handle_cmd drivers/block/loop.c:1705 [inline]
 [<ffffffff82520477>] loop_queue_work+0x12b7/0x1620 drivers/block/loop.c:1717
 [<ffffffff81190c73>] kthread_worker_fn+0x1c3/0x610 kernel/kthread.c:602
 [<ffffffff81190958>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c2b55>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
no locks held by loop0/4304.
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 3708 Comm: rsyslogd Not tainted 4.4.138-g226f96b #61
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800aca1e000 task.stack: ffff8801c7e10000
RIP: 0010:[<ffffffff811a4310>]  [<ffffffff811a4310>] preempt_count_sub+0x0/0x160 include/linux/perf_event.h:939
RSP: 0018:ffff8801c7e17790  EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8801d3b83c00 RCX: 0000000000000009
RDX: 0000000000000000 RSI: ffffffff8151c83c RDI: 0000000000000001
RBP: ffff8801c7e177a0 R08: ffff8801c7e178b8 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffff8000
R13: ffff8801d3b83c28 R14: ffff8801c7e17ce8 R15: 0000000000000000
FS:  00007f62ab921700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000811baec CR3: 00000001c8541000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff812e927a ffff8801d3b83c28 ffff8801c7e177b8 ffffffff8118bf4b
 ffff8801c7e17e50 ffff8801c7e17810 ffffffff810167cb ffff8801c7e17e50
 ffff8801c7e178b8 ffffffff83a10a60 ffff8801c7e10000 ffff8800aca1e000
Call Trace:
 [<ffffffff8118bf4b>] __kernel_text_address+0x6b/0xa0 kernel/extable.c:103
 [<ffffffff810167cb>] print_context_stack+0x4b/0xd0 arch/x86/kernel/dumpstack.c:107
 [<ffffffff81015d0a>] dump_trace+0x17a/0x360 arch/x86/kernel/dumpstack_64.c:243
 [<ffffffff81033e46>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff814f88d3>] save_stack+0x43/0xd0 mm/kasan/kasan.c:512
 [<ffffffff814f8bb7>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff814f8bb7>] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616
 [<ffffffff814f9182>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff814f4f23>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff814f4f23>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff814f4f23>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff814f4f23>] kmem_cache_alloc_trace+0xc3/0x2c0 mm/slub.c:2640
 [<ffffffff8125be03>] kmalloc include/linux/slab.h:476 [inline]
 [<ffffffff8125be03>] syslog_print kernel/printk/printk.c:1148 [inline]
 [<ffffffff8125be03>] do_syslog+0x603/0xb20 kernel/printk/printk.c:1331
 [<ffffffff8169b484>] kmsg_read+0x74/0xa0 fs/proc/kmsg.c:39
 [<ffffffff81671799>] proc_reg_read+0xf9/0x180 fs/proc/inode.c:202
 [<ffffffff8151c83c>] __vfs_read+0x11c/0x3e0 fs/read_write.c:432
 [<ffffffff8151e630>] vfs_read+0x130/0x360 fs/read_write.c:454
 [<ffffffff81520e39>] SYSC_read fs/read_write.c:569 [inline]
 [<ffffffff81520e39>] SyS_read+0xd9/0x1c0 fs/read_write.c:562
 [<ffffffff838c2725>] entry_SYSCALL_64_fastpath+0x22/0x9e
Code: 48 89 45 c8 e8 22 55 35 00 4c 8b 45 c0 48 8b 45 c8 48 8b 55 d0 e9 3f fe ff ff 4c 89 c7 e8 49 55 35 00 e9 8a fe ff ff 0f 1f 40 00 <48> b8 00 00 00 00 00 fc ff df 55 48 89 e5 53 89 fb 48 c7 c7 00 
NMI backtrace for cpu 1
CPU: 1 PID: 492 Comm: khungtaskd Not tainted 4.4.138-g226f96b #61
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb0fb000 task.stack: ffff8800bb3a0000
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfb26>]  [<ffffffff810bfb26>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb3a7cc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bb3a7cf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f6a0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000008148024 CR3: 00000000af378000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f6a0 ffffffff84a18ee0 0000000000000007 fffffbfff0942c8c
 0000000000000040 ffff8800bb3a7d10 ffffffff810b5ae1 ffffffff83c0b460
 0000000000000003 ffff8800bb3a7d68 ffffffff81e19d83 ffff8800b653c800
Call Trace:
 [<ffffffff810b5ae1>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19d83>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5b84>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a459>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a459>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a459>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a459>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190958>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c2b55>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 02