[ale] checking for process in uninterruptable sleep state

[Phil Turmel]

On 05/10/2016 10:39 AM, Todor Fassl wrote:
> Details: I have 15 Dell workstations running ubuntu 15.10 (2 are running
> 16.04 -- that did not help). Occasionally, the keyboard and mouse
> freeze. Logging in remotely and running lsusb hangs such that you can't
> even control-c outand it cannot be killed even with a -9. The process
> goes into an uninterruptable sleep during a system call to open the file
> /sys/bus/usb/devices/usb1/descriptors. That file is part of the kernel's
> control files for the usb controller itself. So you can see why the
> keyboard and mouse are dead, the driver for the usb controller itself is
> hung.

> PS: I wouldn't mind ideas wrt the original problem either. Not that I
> hold out any hope for that.

Ah, you have buggy USB devices.  I've run into this.  I used the kernel
boot parameter usbcore.autosuspend=-1 to globally disable USB per-device
power saving on my mythtv server.  If you can narrow it down to a
specific set of devices, you could create udev rules to prevent just
those from sleeping.

Some links:

http://unix.stackexchange.com/questions/91027/how-to-disable-usb-autosuspend-on-kernel-3-7-10-or-above

http://askubuntu.com/questions/80638/how-to-disable-auto-power-off-of-usb-devices-like-usb-mouse

Phil