Red Hat Bugzilla – Bug 85398
process that hangs and will not be killed
Last modified: 2007-04-18 12:51:44 EDT
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Description of problem:
I run a c program that hangs for some reason (I'm not talking about rpm. I
noticed there were bug reports about rpm hanging but this is
just simple c program). I run the program, it starts running and printing
verbose messages to the screen, then it hangs and the screen
freezes, I try to control-c
out of it but it doesn't work. I then try to kill it using
kill pid then kill -9 pid. It doesn't work. I have had this problem on
two machines that I have upgraded to 8.0. I also look at top and do not see the
process running. If I keep trying to run the program it will hang again and make
another unkillable process. If I reboot the machine and then try to run the
program it runs fine. It happens occasionally and the machine must be rebooted
or the process must be left to hang until a conveniant time to reboot the
machine is found.
So far this has always happened with programs that were reading files
on a nfs mounted partition.
I put this under sh-utils because I thought maybe it's a problem with the kill
command but maybe it belongs elsewhere.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.I run c programs. eventually one hangs
2. If I am not running the program in the background I try to control-c to interrupt
3.I use ps-ax to find the pid number and try to kill the program kill <PID>
then kill -9 <PID>
Actual Results: The program persists. It shows up on ps -ax although not on top.
Expected Results: kill -9 pid should have killed the program
I did not have this problem with redhat7.2.
When this happens, does 'dmesg' show any alarming messages? This sounds like it
might be a kernel problem.
Created attachment 90483 [details]
This was the output of dmesg when I had an unkillable process
The process is in uninterruptable sleep.
Certainly not a sh-utils problem anyway. Changing component.
could you enable magic-sysreq (see the /etc/sysctl.config file) and then press
sysreq-t ? that will spew a lot of stuff but that will usually be the right info
for chasing such uninterruptible hangs.