another two excerpts from syslog

May  1 13:56:47 xpc kernel: [85171.089467] INFO: task section handler:2730 blocked for more than 120 seconds.
May  1 13:56:47 xpc kernel: [85171.089470]       Tainted: G           OE  3.19.0-15-generic #15-Ubuntu
May  1 13:56:47 xpc kernel: [85171.089471] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
May  1 13:56:47 xpc kernel: [85171.089472] section handler D ffff8800b31c7c08     0  2730   2590 0x00000000
May  1 13:56:47 xpc kernel: [85171.089475]  ffff8800b31c7c08 ffff8801b5ee3ae0 0000000000014200 ffff8800b31c7fd8
May  1 13:56:47 xpc kernel: [85171.089477]  0000000000014200 ffff8801b8278000 ffff8801b5ee3ae0 ffff8800b31c7be8
May  1 13:56:47 xpc kernel: [85171.089478]  ffff8801400bbf10 7fffffffffffffff ffff8801400bbf08 ffff8801b5ee3ae0
May  1 13:56:47 xpc kernel: [85171.089480] Call Trace:
May  1 13:56:47 xpc kernel: [85171.089486]  [<ffffffff817c49c9>] schedule+0x29/0x70
May  1 13:56:47 xpc kernel: [85171.089489]  [<ffffffff817c7fac>] schedule_timeout+0x20c/0x280
May  1 13:56:47 xpc kernel: [85171.089494]  [<ffffffff811811a7>] ? __free_pages+0x27/0x30
May  1 13:56:47 xpc kernel: [85171.089496]  [<ffffffff811811f0>] ? free_pages.part.67+0x40/0x50
May  1 13:56:47 xpc kernel: [85171.089497]  [<ffffffff81181213>] ? free_pages+0x13/0x20
May  1 13:56:47 xpc kernel: [85171.089499]  [<ffffffff817c6384>] wait_for_completion+0xa4/0x170
May  1 13:56:47 xpc kernel: [85171.089502]  [<ffffffff810a1dd0>] ? wake_up_state+0x20/0x20
May  1 13:56:47 xpc kernel: [85171.089505]  [<ffffffff810949d3>] kthread_stop+0x53/0x100
May  1 13:56:47 xpc kernel: [85171.089517]  [<ffffffffc06d1aa4>] vb2_thread_stop+0x64/0xd0 [videobuf2_core]
May  1 13:56:47 xpc kernel: [85171.089519]  [<ffffffffc077113e>] vb2_dvb_stop_feed+0x4e/0x70 [videobuf2_dvb]
May  1 13:56:47 xpc kernel: [85171.089524]  [<ffffffffc07156ab>] dmx_section_feed_stop_filtering+0x4b/0xe0 [dvb_core]
May  1 13:56:47 xpc kernel: [85171.089527]  [<ffffffffc0712b5b>] dvb_dmxdev_feed_stop+0xeb/0x100 [dvb_core]
May  1 13:56:47 xpc kernel: [85171.089530]  [<ffffffffc0712d5c>] dvb_dmxdev_filter_stop+0x9c/0xe0 [dvb_core]
May  1 13:56:47 xpc kernel: [85171.089533]  [<ffffffffc0713248>] dvb_demux_release+0x48/0x260 [dvb_core]
May  1 13:56:47 xpc kernel: [85171.089537]  [<ffffffff811f4f97>] __fput+0xe7/0x250
May  1 13:56:47 xpc kernel: [85171.089539]  [<ffffffff811f514e>] ____fput+0xe/0x10
May  1 13:56:47 xpc kernel: [85171.089541]  [<ffffffff81092d24>] task_work_run+0xd4/0xf0
May  1 13:56:47 xpc kernel: [85171.089544]  [<ffffffff81014ff7>] do_notify_resume+0x97/0xb0
May  1 13:56:47 xpc kernel: [85171.089546]  [<ffffffff817c95ef>] int_signal+0x12/0x17

May  1 13:58:47 xpc kernel: [85291.048580] INFO: task section handler:2730 blocked for more than 120 seconds.
May  1 13:58:47 xpc kernel: [85291.048584]       Tainted: G           OE  3.19.0-15-generic #15-Ubuntu
May  1 13:58:47 xpc kernel: [85291.048585] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
May  1 13:58:47 xpc kernel: [85291.048586] section handler D ffff8800b31c7c08     0  2730   2590 0x00000000
May  1 13:58:47 xpc kernel: [85291.048589]  ffff8800b31c7c08 ffff8801b5ee3ae0 0000000000014200 ffff8800b31c7fd8
May  1 13:58:47 xpc kernel: [85291.048590]  0000000000014200 ffff8801b8278000 ffff8801b5ee3ae0 ffff8800b31c7be8
May  1 13:58:47 xpc kernel: [85291.048592]  ffff8801400bbf10 7fffffffffffffff ffff8801400bbf08 ffff8801b5ee3ae0
May  1 13:58:47 xpc kernel: [85291.048593] Call Trace:
May  1 13:58:47 xpc kernel: [85291.048599]  [<ffffffff817c49c9>] schedule+0x29/0x70
May  1 13:58:47 xpc kernel: [85291.048601]  [<ffffffff817c7fac>] schedule_timeout+0x20c/0x280
May  1 13:58:47 xpc kernel: [85291.048605]  [<ffffffff811811a7>] ? __free_pages+0x27/0x30
May  1 13:58:47 xpc kernel: [85291.048607]  [<ffffffff811811f0>] ? free_pages.part.67+0x40/0x50
May  1 13:58:47 xpc kernel: [85291.048608]  [<ffffffff81181213>] ? free_pages+0x13/0x20
May  1 13:58:47 xpc kernel: [85291.048610]  [<ffffffff817c6384>] wait_for_completion+0xa4/0x170
May  1 13:58:47 xpc kernel: [85291.048612]  [<ffffffff810a1dd0>] ? wake_up_state+0x20/0x20
May  1 13:58:47 xpc kernel: [85291.048615]  [<ffffffff810949d3>] kthread_stop+0x53/0x100
May  1 13:58:47 xpc kernel: [85291.048627]  [<ffffffffc06d1aa4>] vb2_thread_stop+0x64/0xd0 [videobuf2_core]
May  1 13:58:47 xpc kernel: [85291.048629]  [<ffffffffc077113e>] vb2_dvb_stop_feed+0x4e/0x70 [videobuf2_dvb]
May  1 13:58:47 xpc kernel: [85291.048634]  [<ffffffffc07156ab>] dmx_section_feed_stop_filtering+0x4b/0xe0 [dvb_core]
May  1 13:58:47 xpc kernel: [85291.048637]  [<ffffffffc0712b5b>] dvb_dmxdev_feed_stop+0xeb/0x100 [dvb_core]
May  1 13:58:47 xpc kernel: [85291.048640]  [<ffffffffc0712d5c>] dvb_dmxdev_filter_stop+0x9c/0xe0 [dvb_core]
May  1 13:58:47 xpc kernel: [85291.048642]  [<ffffffffc0713248>] dvb_demux_release+0x48/0x260 [dvb_core]
May  1 13:58:47 xpc kernel: [85291.048646]  [<ffffffff811f4f97>] __fput+0xe7/0x250
May  1 13:58:47 xpc kernel: [85291.048647]  [<ffffffff811f514e>] ____fput+0xe/0x10
May  1 13:58:47 xpc kernel: [85291.048649]  [<ffffffff81092d24>] task_work_run+0xd4/0xf0
May  1 13:58:47 xpc kernel: [85291.048652]  [<ffffffff81014ff7>] do_notify_resume+0x97/0xb0
May  1 13:58:47 xpc kernel: [85291.048654]  [<ffffffff817c95ef>] int_signal+0x12/0x17