Re: [LTP] [PATCH 1/1 1/1] Add ioctl_loop08 test for LOOP_GET_STATUS lock imbalance

Cyril Hrubis
2023-02-10T12:12:29Z

Hi!
> Sincere thanks for your advice.
> Based on my tests，the lockdep will block the ioctl request thread return to
> userspace when it detect a lock imbalance. Place ioctl request in the main
> thread, there is no chance to execute find_kmsg for determining what
> exactly a lock problem happaned and printing the test result.

Hmm, then maybe it would be easier and more reliable to run the ioctl()
in a child processes and fail the test when the parent detects the
child to lockup.

I suppose that the process that called the ioctl() ends up in the D
state, right? In that case the parent read the /proc/pid/stat a few
times with slight delays between them and if the process keeps hanging
in D state we declare it blocked forever.

--
Cyril Hrubis
chrubis@suse.cz