diff options
| author | David Rientjes | 2012-11-12 17:53:04 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2012-11-16 10:15:35 -0800 |
| commit | fa0cbbf145aabbf29c6f28f8a11935c0b0fd86fc (patch) | |
| tree | fd2626b68b0f78afa128d7772c49f066e339bd3a /Documentation/filesystems | |
| parent | f4bcd79c88d25508643084e6fed25920485db0eb (diff) | |
mm, oom: reintroduce /proc/pid/oom_adj
This is mostly a revert of 01dc52ebdf47 ("oom: remove deprecated oom_adj")
from Davidlohr Bueso.
It reintroduces /proc/pid/oom_adj for backwards compatibility with earlier
kernels. It simply scales the value linearly when /proc/pid/oom_score_adj
is written.
The major difference is that its scheduled removal is no longer included
in Documentation/feature-removal-schedule.txt. We do warn users with a
single printk, though, to suggest the more powerful and supported
/proc/pid/oom_score_adj interface.
Reported-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a1793d670cd0..3844d21d6ca3 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -33,7 +33,7 @@ Table of Contents 2 Modifying System Parameters 3 Per-Process Parameters - 3.1 /proc/<pid>/oom_score_adj - Adjust the oom-killer + 3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj - Adjust the oom-killer score 3.2 /proc/<pid>/oom_score - Display current oom-killer score 3.3 /proc/<pid>/io - Display the IO accounting fields @@ -1320,10 +1320,10 @@ of the kernel. CHAPTER 3: PER-PROCESS PARAMETERS ------------------------------------------------------------------------------ -3.1 /proc/<pid>/oom_score_adj- Adjust the oom-killer score +3.1 /proc/<pid>/oom_adj & /proc/<pid>/oom_score_adj- Adjust the oom-killer score -------------------------------------------------------------------------------- -This file can be used to adjust the badness heuristic used to select which +These file can be used to adjust the badness heuristic used to select which process gets killed in out of memory conditions. The badness heuristic assigns a value to each candidate task ranging from 0 @@ -1361,6 +1361,12 @@ same system, cpuset, mempolicy, or memory controller resources to use at least equivalent to discounting 50% of the task's allowed memory from being considered as scoring against the task. +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 may be reduced no lower than the last value set by a CAP_SYS_RESOURCE process. To reduce the value any lower requires CAP_SYS_RESOURCE. @@ -1375,7 +1381,9 @@ minimal amount of work. ------------------------------------------------------------- This file can be used to check the current score used by the oom-killer is for -any given <pid>. +any given <pid>. Use it together with /proc/<pid>/oom_score_adj to tune which +process should be killed in an out-of-memory situation. + 3.3 /proc/<pid>/io - Display the IO accounting fields ------------------------------------------------------- |