The waiting channel value is the name of the kernel function in which the
process is currently blocked.
The name is usually related to a system call, which will have a
- futex_wait_queue_me is related to futex. It refers to a type of mutex lock (fast userspace mutual exclusion) that is used to schedule many processes work on one processor. The state indicates that your process is enqueued to receive the lock. 2
- do_wait is related to wait.
If you really want more detailed information you could check the kernel source.
If you type
cat /proc/some_pid/stack in a terminal you'll get some output like that one :
And on the first line you get what's displayed on the system monitor. As far as I know, poll_schedule_timeout indicates that your process is waiting for something.
It deals with asynchronous I/O and polling.
Source(s) : 1. process wait channel (WCHAN) and alarm? - 2. AskUbuntu answer