Sometimes when my terminal freezes up and it will not let me type. I can not identify any causes, nor how to diagnose. Any suggestions?
GNOME Terminal 2.30.2 on Ubuntu 10.04
A good general way to diagnose mysterious hangs:
ps axo pid,wchan:32,cmdto find the other process id
wchancolumn, which should tell you whether it's stuck in the kernel
sudo strace -p PIDinserting the pid of that process; paste that into a bug report or question
If there's anything aside from just a dash in the wchan column, then the process is in the kernel doing something. Some typical values:
futex_wait_queue_me- waiting on a futex for another thread in the same process
poll_schedule_timeout- waiting for network or interprocess communication, or just sleeping for a while
pipe_wait- reading/writing a pipe
There are thousands of possibilities so I can't list them all. See What is the "Waiting Channel" of a process? for more.