Part Number: AM3358
Tool/software: Linux
In customer system, connected a 4G USB module on USB0, when the module has a sim card inserted, system works right. if no sim card, the application power off and power up the USB module every 2 minutes, kernel message as below:
after a while of power up/power down cycle of the module, system loading became very high as below:
According to some suggestion from internet to found out what is the thread result in high loading:
1、echo workqueue:workqueue_queue_work > /sys/kernel/debug/tracing/set_event
2、cat /sys/kernel/debug/tracing/trace_pipe > out.txt
3、mount -t debugfs nodev /sys/kernel/debug
4、cat /proc/THE_OFFENDING_KWORKER/stack
Snapshot of out.txt as below:
root@am335x-evm:~# cat /proc/13/stack
[<c075b490>] musb_urb_dequeue+0xf4/0x1f0
[<c06fcae8>] unlink1+0x3c/0x150
[<c06ff048>] usb_hcd_unlink_urb+0xa8/0xc8
[<c06ffd68>] usb_unlink_urb+0x3c/0x58
[<c06f07dc>] unlink_urbs.constprop.11+0xec/0x12c
[<c06f0c64>] __handle_link_change.part.5+0x80/0x84
[<c06f0f48>] usbnet_deferred_kevent+0x2e0/0x380
[<c0146cd8>] process_one_work+0x214/0x554
[<c01470a4>] worker_thread+0x8c/0x688
[<c014d29c>] kthread+0x168/0x170
[<c0108268>] ret_from_fork+0x14/0x2c
[<ffffffff>] 0xffffffff
Would somebody help analysis what result in system high loading?
