INFO: task loop0:14333 blocked for more than 120 seconds. Not tainted 4.4.120-gd63fdf6 #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. loop0 D ffff8800ba6dede0 26904 14333 2 0x00000000 ffff8800ba6dede0 ffffffff83fb2270 ffffffff81237410 0000000000000000 0000000000000000 0000000000000000 ffff8801db31fdb8 ffff8801db31fde0 ffff8801db31f4d8 ffff8801d8dfe000 ffff8800a97d1800 ffff8800ba6df670 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3353 [] schedule_timeout+0x3a0/0x970 kernel/time/timer.c:1515 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4935 [] io_schedule include/linux/sched.h:447 [inline] [] bt_get+0x305/0x760 block/blk-mq-tag.c:301 [] __blk_mq_get_tag block/blk-mq-tag.c:325 [inline] [] blk_mq_get_tag+0x1eb/0x340 block/blk-mq-tag.c:353 [] __blk_mq_alloc_request+0x24/0xa50 block/blk-mq.c:215 [] blk_mq_map_request+0x8d1/0xde0 block/blk-mq.c:1190 [] blk_sq_make_request+0x1a0/0xfc0 block/blk-mq.c:1361 [] generic_make_request+0x311/0x990 block/blk-core.c:2081 [] submit_bio+0x17a/0x540 block/blk-core.c:2154 [] dio_bio_submit fs/direct-io.c:409 [inline] [] do_blockdev_direct_IO+0x6ba8/0x8810 fs/direct-io.c:1283 [] __blockdev_direct_IO+0xae/0xe0 fs/direct-io.c:1342 [] blkdev_direct_IO+0xb2/0xe0 fs/block_dev.c:167 [] generic_file_read_iter+0x360/0x1160 mm/filemap.c:1791 [] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1679 [] lo_rw_aio drivers/block/loop.c:506 [inline] [] lo_rw_simple drivers/block/loop.c:520 [inline] [] do_req_filebacked drivers/block/loop.c:558 [inline] [] loop_handle_cmd drivers/block/loop.c:1698 [inline] [] loop_queue_work+0x1eac/0x31c0 drivers/block/loop.c:1710 [] kthread_worker_fn+0x27b/0x600 kernel/kthread.c:602 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:506 no locks held by loop0/14333. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffffffff84217840 task.stack: ffffffff84200000 RIP: 0010:[] [] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:49 RSP: 0018:ffffffff84207dc0 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffffffff847ddc08 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8421810c RBP: ffffffff84207dc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: fffffbfff070889c R14: ffffffff847ebf78 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f04c95c1000 CR3: 00000000b3aa6000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff84207df8 ffffffff81027e85 ffffffff84208000 ffffffff847ddc08 fffffbfff070889c ffffffff847ebf78 0000000000000000 ffffffff84207e08 ffffffff810293fa ffffffff84207e20 ffffffff81221468 dffffc0000000000 Call Trace: [] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:290 [] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:281 [] default_idle_call+0x48/0x70 kernel/sched/idle.c:93 [] cpuidle_idle_call kernel/sched/idle.c:157 [inline] [] cpu_idle_loop kernel/sched/idle.c:253 [inline] [] cpu_startup_entry+0x5fd/0x8f0 kernel/sched/idle.c:301 [] rest_init+0x189/0x190 init/main.c:410 [] start_kernel+0x6b9/0x6ee init/main.c:682 [] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:196 [] x86_64_start_kernel+0x140/0x163 arch/x86/kernel/head64.c:185 Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84 NMI backtrace for cpu 1 CPU: 1 PID: 485 Comm: khungtaskd Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bac00000 task.stack: ffff8800bb3e0000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline] RIP: 0010:[] [] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline] RIP: 0010:[] [] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline] RIP: 0010:[] [] flat_send_IPI_mask+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8800bb3e7cb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bb3e7ce0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: ffffffff8426f420 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000c899d0 CR3: 00000000b3aa6000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426f420 ffffffff847efb00 fffffbfff08fda14 dffffc0000000000 ffff8801db31bca0 ffff8800bb3e7d00 ffffffff810b999b ffffffff839f63c0 0000000000000003 ffff8800bb3e7d60 ffffffff81d0eff4 0000000000000000 Call Trace: [] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 lib/nmi_backtrace.c:85 [] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 [] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6fa/0xae0 kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:506 Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 6b 2f 17 00 4c 89 e7 57 9d 0f 1f