Introduction

Setting process limits can be helpful especially to students in operating systems classes where there is the risk of uncontrollable process forks.

Setting Process Limits

1. When you first log in enter limit maxproc 40. This will limit your current *shell* to 40 processes.
   • CSE 421 and 521 students should be using fork.cse.buffalo.edu
   • We set the system wide value on this machine to 50 process per user. Because you set your shell limit to 40 processes you still have 10 processes to spare if something begins fork uncontrollably.
2. You can then start a second SSH shell to the machine with the runaway processes (with the remaining 10 processes) and kill off what you need to.

Killing Processes

1. Using skill [username] or pkill [process name] can usually make short work of things.
2. Use ps -aux to get the "tty" from your first maxed out shell. Then you can use something like killall -t [tty #] to remove all the processes from that first maxed out shell.

Notes

1. CSE sets RHEL systemwide maxproc limits in:

   
   /util/etc/csh.cshrc