How to prevent a process to be a target of oom-killer?
环境
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
问题
- Important applications killed by oom-killer when there's memory starvation
- How could we prevent this process killed by oom-killer
决议
- This can be achived by using '-17' in oom_adj (RHEL5) or oom_score_adj (RHEL6/7).
- Here's the way to set it.
- RHEL5
Raw
$ echo '-17' > /proc/<pid>/oom_adj
- RHEL6/7
Raw
$ echo '-1000' > /proc/<pid>/oom_score_adj
- From /usr/share/doc/kernel-doc-/Documentation/filesystems/proc.txt
Raw
For backwards compatibility with previous kernels, /proc/<pid>/oom_adj may also
be used to tune the badness score. Its acceptable values range from -16
(OOM_ADJUST_MIN) to +15 (OOM_ADJUST_MAX) and a special value of -17
(OOM_DISABLE) to disable oom killing entirely for that task. Its value is
scaled linearly with /proc/<pid>/oom_score_adj.
The value of /proc/<pid>/oom_score_adj is added to the badness score before it
is used to determine which task to kill. Acceptable values range from -1000
(OOM_SCORE_ADJ_MIN) to +1000 (OOM_SCORE_ADJ_MAX). This allows userspace to
polarize the preference for oom killing either by always preferring a certain
task or completely disabling it. The lowest possible value, -1000, is
equivalent to disabling oom killing entirely for that task since it will always
report a badness score of 0.
