Comment 2 for bug 1451009

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