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    SubjectOOM documentation update [was: Linux killed Kenny, bastard!]
    Please apply.
    While existing interface do not fix the problems, they should be at least documented.

    Sign.

    diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
    index d105eb4..f7530a1 100644
    --- a/Documentation/filesystems/proc.txt
    +++ b/Documentation/filesystems/proc.txt
    @@ -2311,6 +2311,30 @@ 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.

    +Process to be killed at out-of-memory situation is selected among all others
    +based on its badness score. This value equals to the memory size of the process
    +originally and then changed 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 devided by the sqare root of the cpu time and then by
    +the double square root of the run time.
    +
    +/proc/<pid>/oom_score shows process' current badness score.
    +
    +Following heueristics are then applied:
    + * if 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
    + * resulted score is multiplied by the two in the power of oom_adj when it is
    + positive, and devided otherwise, i.e.
    + points <<= oom_adj when it is positive and
    + points >>= oom_adj otherwise
    +
    +Swapped tasks are killed first.
    +Task with the biggest number of badness points is selected to be killed.
    +Usually children tasks are prefered compared to their parent.
    +
    2.13 /proc/<pid>/oom_score - Display current oom-killer score
    -------------------------------------------------------------


    --
    Evgeniy Polyakov


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