How do I determine and configure the likelihood that a process will be killed in a out-of-memory situation?

Updated

Issue

  • How to adjust a process score calculations for Out-of-memory situations

Environment

  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 5

Resolution

It is possible to adjust the oom-score for each process on the system. In the '/proc' file system, there are 2 files for each system enlisted task that provide control over the likelihood that a proccess should be terminated. These files are:

  • /proc/[pid]/oom_adj — Used to adjust the "OOM score", which determines the likelihood of a process being killed in an out-of-memory situation. A higher OOM score means a higher likelihood that the process will be killed by oomkill. Valid values are -17 to 15; note that an OOM score of -17 means [pid] will never be killed. 
     
      To specify an OOM score, simply echo the score to /proc/[pid]/oom_adj. For example, to set an OOM score of 15 to [pid] 1111, run:

    echo 15 > /proc/1111/oom_adj


     
      Note that the OOM score is inherited from parent processes to child processes during fork() operations.

  • /proc/[pid]/oom_score — Displays the current OOM score for a given process. Use cat to display the current OOM score for [pid]. For example, to view the current OOM score for [pid] 1111, run:

    cat /proc/1111/oom_score
Product(s)
Tags