INFO: task swapper/0:1 blocked for more than 120 seconds.
      Not tainted 4.6.0-rc1+ #52
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
swapper/0       D ffff000008086c40     0     1      0 0x00000000
Call trace:
[<ffff000008086c40>] __switch_to+0xd0/0xdc
[<ffff00000868d544>] __schedule+0x1b0/0x57c
[<ffff00000868d950>] schedule+0x40/0xa4
[<ffff000008690384>] schedule_timeout+0x154/0x1a0
[<ffff00000868d320>] io_schedule_timeout+0xa0/0x114
[<ffff00000868e208>] bit_wait_io+0x14/0x64
[<ffff00000868de70>] __wait_on_bit+0xa4/0xd8
[<ffff00000814d300>] wait_on_page_bit+0x7c/0x84
[<ffff00000814dd7c>] do_read_cache_page+0x1c8/0x374
[<ffff00000814df3c>] read_cache_page+0x14/0x1c
[<ffff00000831e560>] read_dev_sector+0x30/0xd4
[<ffff000008320c90>] read_lba+0xe0/0x1a0
[<ffff0000083210a0>] find_valid_gpt+0xb4/0x4a0
[<ffff0000083214ec>] efi_partition+0x60/0x3a4
[<ffff0000083200d0>] check_partition+0xfc/0x200
[<ffff00000831ebdc>] rescan_partitions+0xc8/0x2c4
[<ffff0000081ec5c8>] __blkdev_get+0x250/0x318
[<ffff0000081ec814>] blkdev_get+0x184/0x300
[<ffff00000831c5d8>] add_disk+0x398/0x408
[<ffff000008413768>] virtblk_probe+0x3f8/0x6b8
[<ffff0000083a660c>] virtio_dev_probe+0x138/0x21c
[<ffff0000083f3b10>] driver_probe_device+0x1fc/0x29c
[<ffff0000083f3c54>] __driver_attach+0xa4/0xa8
[<ffff0000083f1c3c>] bus_for_each_dev+0x58/0x98
[<ffff0000083f343c>] driver_attach+0x20/0x28
[<ffff0000083f3058>] bus_add_driver+0x1c8/0x22c
[<ffff0000083f44ec>] driver_register+0x68/0x108
[<ffff0000083a6428>] register_virtio_driver+0x20/0x34
[<ffff0000089238c8>] init+0x6c/0xac
[<ffff000008082a08>] do_one_initcall+0x8c/0x1a0
[<ffff0000088ffae4>] kernel_init_freeable+0x148/0x1ec
[<ffff00000868b578>] kernel_init+0x10/0xe8
[<ffff000008085e10>] ret_from_fork+0x10/0x40