Re: [PATCH v6 2/2] misc: Add a mechanism to detect stalls on guest vCPUs

From: Greg Kroah-Hartman
Date: Thu Jun 16 2022 - 06:09:10 EST


On Thu, Jun 16, 2022 at 09:27:39AM +0000, Sebastian Ene wrote:
> This driver creates per-cpu hrtimers which are required to do the
> periodic 'pet' operation. On a conventional watchdog-core driver, the
> userspace is responsible for delivering the 'pet' events by writing to
> the particular /dev/watchdogN node. In this case we require a strong
> thread affinity to be able to account for lost time on a per vCPU.
>
> This part of the driver is the 'frontend' which is reponsible for
> delivering the periodic 'pet' events, configuring the virtual peripheral
> and listening for cpu hotplug events. The other part of the driver
> handles the peripheral emulation and this part accounts for lost time by
> looking at the /proc/{}/task/{}/stat entries and is located here:
> https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3548817
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

The robot reported stalls on vcpus?

I think you need to fix this up...

greg k-h