diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-01-31 17:32:31 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-02-05 22:30:01 +0100 |
| commit | 9d45cf9e36bf9bcf16df6e1cbf049807c8402823 (patch) | |
| tree | 2118a16701418af10d215d2174df7ee0a5cbe6bd /Documentation/filesystems/proc.txt | |
| parent | a146649bc19d5eba4f5bfac6720c5f252d517a71 (diff) | |
| parent | 0cd5c3c80a0ebd68c08312fa7d8c13149cc61c4c (diff) | |
| download | kernel_samsung_smdk4412-9d45cf9e36bf9bcf16df6e1cbf049807c8402823.tar.gz kernel_samsung_smdk4412-9d45cf9e36bf9bcf16df6e1cbf049807c8402823.tar.bz2 kernel_samsung_smdk4412-9d45cf9e36bf9bcf16df6e1cbf049807c8402823.zip | |
Merge branch 'x86/urgent' into x86/apic
Conflicts:
arch/x86/mach-default/setup.c
Semantic merge:
arch/x86/kernel/irqinit_32.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index bbebc3a43ac..a87be42f821 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -2027,6 +2027,34 @@ increase the likelihood of this process being killed by the oom-killer. Valid values are in the range -16 to +15, plus the special value -17, which disables oom-killing altogether for this process. +The process to be killed in an out-of-memory situation is selected among all others +based on its badness score. This value equals the original memory size of the process +and is then updated according to its CPU time (utime + stime) and the +run time (uptime - start time). The longer it runs the smaller is the score. +Badness score is divided by the square root of the CPU time and then by +the double square root of the run time. + +Swapped out tasks are killed first. Half of each child's memory size is added to +the parent's score if they do not share the same memory. Thus forking servers +are the prime candidates to be killed. Having only one 'hungry' child will make +parent less preferable than the child. + +/proc/<pid>/oom_score shows process' current badness score. + +The following heuristics are then applied: + * if the task was reniced, its score doubles + * superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE + or CAP_SYS_RAWIO) have their score divided by 4 + * if oom condition happened in one cpuset and checked task does not belong + to it, its score is divided by 8 + * the resulting score is multiplied by two to the power of oom_adj, i.e. + points <<= oom_adj when it is positive and + points >>= -(oom_adj) otherwise + +The task with the highest badness score is then selected and its children +are killed, process itself will be killed in an OOM situation when it does +not have children or some of them disabled oom like described above. + 2.13 /proc/<pid>/oom_score - Display current oom-killer score ------------------------------------------------------------- |