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Kernel panic: hung_task [...] blocked for more than 120 seconds

Posted: Tue Nov 27, 2018 8:51 pm
by arajasek
I'm using a raspberry pi with a pi camera for a video monitoring setup. I often (once a week) get this error where the pi freezes, stops recording video. I can't restart the video record service. If I do sudo reboot, the shutdown process never completes and the system is in limbo. I have to do a power cycle to reboot the pi. The two most common causes listed on other posts are power supply and SD card corruption. There are no under-voltage errors and the power supply is rated for 2.5Amps. I don't think it's an SD card corruption as the pi boots up fine from the same SD card after a power cycle. The kern log when the error starts to happen is pasted below. Any help figuring out the cause of this problem is much appreciated.

Code: Select all

Nov 18 08:00:24 c0001001 kernel: [    5.887875] random: crng init done
Nov 18 08:00:24 c0001001 kernel: [    6.347310] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
Nov 18 08:00:24 c0001001 kernel: [    7.242765] Adding 102396k swap on /var/swap.  Priority:-1 extents:3 across:249852k SSFS
Nov 18 08:00:25 c0001001 kernel: [    8.470365] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
Nov 18 16:34:17 c0001001 kernel: [30840.984841] INFO: task kworker/1:2:1486 blocked for more than 120 seconds.
Nov 18 16:34:17 c0001001 kernel: [30840.984854]       Tainted: G           O    4.9.35-v7+ #1014
Nov 18 16:34:17 c0001001 kernel: [30840.984858] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Nov 18 16:34:17 c0001001 kernel: [30840.984864] kworker/1:2     D    0  1486      2 0x00000000
Nov 18 16:34:17 c0001001 kernel: [30840.984895] Workqueue: events dbs_work_handler
Nov 18 16:34:17 c0001001 kernel: [30840.984928] [<807146b0>] (__schedule) from [<80714bd4>] (schedule+0x50/0xa8)
Nov 18 16:34:17 c0001001 kernel: [30840.984944] [<80714bd4>] (schedule) from [<80717e44>] (schedule_timeout+0x220/0x364)
Nov 18 16:34:17 c0001001 kernel: [30840.984960] [<80717e44>] (schedule_timeout) from [<80715748>] (wait_for_common+0xbc/0x17c)
Nov 18 16:34:17 c0001001 kernel: [30840.984978] [<80715748>] (wait_for_common) from [<80715828>] (wait_for_completion+0x20/0x24)
Nov 18 16:34:17 c0001001 kernel: [30840.984995] [<80715828>] (wait_for_completion) from [<805d9c30>] (rpi_firmware_transaction+0x68/0xac)
Nov 18 16:34:17 c0001001 kernel: [30840.985011] [<805d9c30>] (rpi_firmware_transaction) from [<805d9d6c>] (rpi_firmware_property_list+0xf8/0x220)
Nov 18 16:34:17 c0001001 kernel: [30840.985027] [<805d9d6c>] (rpi_firmware_property_list) from [<805d9ef8>] (rpi_firmware_property+0x64/0x84)
Nov 18 16:34:17 c0001001 kernel: [30840.985042] [<805d9ef8>] (rpi_firmware_property) from [<805b51e4>] (bcm2835_cpufreq_clock_property.constprop.1+0x48/0x5c)
Nov 18 16:34:17 c0001001 kernel: [30840.985057] [<805b51e4>] (bcm2835_cpufreq_clock_property.constprop.1) from [<805b5244>] (bcm2835_cpufreq_driver_target_index+0x4c/0xc0)
Nov 18 16:34:17 c0001001 kernel: [30840.985072] [<805b5244>] (bcm2835_cpufreq_driver_target_index) from [<805af4b0>] (__cpufreq_driver_target+0x250/0x580)
Nov 18 16:34:17 c0001001 kernel: [30840.985089] [<805af4b0>] (__cpufreq_driver_target) from [<805b3990>] (od_dbs_timer+0xa8/0x174)
Nov 18 16:34:17 c0001001 kernel: [30840.985106] [<805b3990>] (od_dbs_timer) from [<805b4608>] (dbs_work_handler+0x3c/0x68)
Nov 18 16:34:17 c0001001 kernel: [30840.985126] [<805b4608>] (dbs_work_handler) from [<80136660>] (process_one_work+0x158/0x454)
Nov 18 16:34:17 c0001001 kernel: [30840.985145] [<80136660>] (process_one_work) from [<801369c0>] (worker_thread+0x64/0x568)
Nov 18 16:34:17 c0001001 kernel: [30840.985161] [<801369c0>] (worker_thread) from [<8013c8c8>] (kthread+0x10c/0x124)
Nov 18 16:34:17 c0001001 kernel: [30840.985177] [<8013c8c8>] (kthread) from [<80108148>] (ret_from_fork+0x14/0x2c)
Nov 18 16:36:19 c0001001 kernel: [30963.864845] INFO: task kworker/1:2:1486 blocked for more than 120 seconds.
Nov 18 16:36:19 c0001001 kernel: [30963.864858]       Tainted: G           O    4.9.35-v7+ #1014
Nov 18 16:36:19 c0001001 kernel: [30963.864863] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Nov 18 16:36:19 c0001001 kernel: [30963.864868] kworker/1:2     D    0  1486      2 0x00000000
Nov 18 16:36:19 c0001001 kernel: [30963.864900] Workqueue: events dbs_work_handler
Nov 18 16:36:19 c0001001 kernel: [30963.864932] [<807146b0>] (__schedule) from [<80714bd4>] (schedule+0x50/0xa8)
Nov 18 16:36:19 c0001001 kernel: [30963.864949] [<80714bd4>] (schedule) from [<80717e44>] (schedule_timeout+0x220/0x364)
Nov 18 16:36:19 c0001001 kernel: [30963.864965] [<80717e44>] (schedule_timeout) from [<80715748>] (wait_for_common+0xbc/0x17c)
Nov 18 16:36:19 c0001001 kernel: [30963.864982] [<80715748>] (wait_for_common) from [<80715828>] (wait_for_completion+0x20/0x24)
Nov 18 16:36:19 c0001001 kernel: [30963.865000] [<80715828>] (wait_for_completion) from [<805d9c30>] (rpi_firmware_transaction+0x68/0xac)
Nov 18 16:36:19 c0001001 kernel: [30963.865016] [<805d9c30>] (rpi_firmware_transaction) from [<805d9d6c>] (rpi_firmware_property_list+0xf8/0x220)
Nov 18 16:36:19 c0001001 kernel: [30963.865032] [<805d9d6c>] (rpi_firmware_property_list) from [<805d9ef8>] (rpi_firmware_property+0x64/0x84)
Nov 18 16:36:19 c0001001 kernel: [30963.865047] [<805d9ef8>] (rpi_firmware_property) from [<805b51e4>] (bcm2835_cpufreq_clock_property.constprop.1+0x48/0x5c)
Nov 18 16:36:19 c0001001 kernel: [30963.865062] [<805b51e4>] (bcm2835_cpufreq_clock_property.constprop.1) from [<805b5244>] (bcm2835_cpufreq_driver_target_index+0x4c/0xc0)
Nov 18 16:36:19 c0001001 kernel: [30963.865077] [<805b5244>] (bcm2835_cpufreq_driver_target_index) from [<805af4b0>] (__cpufreq_driver_target+0x250/0x580)
Nov 18 16:36:19 c0001001 kernel: [30963.865094] [<805af4b0>] (__cpufreq_driver_target) from [<805b3990>] (od_dbs_timer+0xa8/0x174)
Nov 18 16:36:19 c0001001 kernel: [30963.865111] [<805b3990>] (od_dbs_timer) from [<805b4608>] (dbs_work_handler+0x3c/0x68)
Nov 18 16:36:19 c0001001 kernel: [30963.865131] [<805b4608>] (dbs_work_handler) from [<80136660>] (process_one_work+0x158/0x454)
Nov 18 16:36:19 c0001001 kernel: [30963.865150] [<80136660>] (process_one_work) from [<801369c0>] (worker_thread+0x64/0x568)
Nov 18 16:36:19 c0001001 kernel: [30963.865166] [<801369c0>] (worker_thread) from [<8013c8c8>] (kthread+0x10c/0x124)
Nov 18 16:36:19 c0001001 kernel: [30963.865182] [<8013c8c8>] (kthread) from [<80108148>] (ret_from_fork+0x14/0x2c)

Re: Kernel panic: hung_task [...] blocked for more than 120 seconds

Posted: Thu Jan 17, 2019 11:52 am
by mohit1
Having same issue?

You find the solution ?

Re: Kernel panic: hung_task [...] blocked for more than 120 seconds

Posted: Mon Jan 28, 2019 1:58 am
by maaw
Same issue here. In my case, this issue started happening after a sudo apt dist-upgrade, so I don't think the sdcard is to blame, although I cannot rule it out. Sometimes the camera works, sometimes it doesn't. Sometimes a raspistill will work but then the camera will not be accessible anymore.
A sudo reboot fails and leaves the Raspberry unreachable via ssh and requiring a power cycle.
I also tried rpi-update and every other thing I could think of.