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    SubjectRe: [PATCH 2/2] oom: give bonus to frozen processes
    On Mon, 26 Sep 2011 02:02:59 -0700 (PDT)
    David Rientjes <> wrote:

    > On Mon, 26 Sep 2011, Michal Hocko wrote:
    > > Let's try it with a heuristic change first. If you really do not like
    > > it, we can move to oom_scode_adj. I like the heuristic change little bit
    > > more because it is at the same place as the root bonus.
    > The problem with the bonus is that, as mentioned previously, it doesn't
    > protect against ANYTHING for the case you're trying to fix. This won't
    > panic the machine because all killable threads are guaranteed to have a
    > non-zero badness score, but it's a very valid configuration to have either
    > - all eligible threads (system-wide, shared cpuset, shared mempolicy
    > nodes) are frozen, or
    > - all eligible frozen threads use <5% of memory whereas all other
    > eligible killable threads use 1% of available memory.
    > and that means the oom killer will repeatedly select those threads and the
    > livelock still exists unless you can guarantee that they are successfully
    > thawed, that thawing them in all situations is safe, and that once thawed
    > they will make a timely exit.
    > Additionally, I don't think biasing against frozen tasks makes sense from
    > a heusritic standpoint of the oom killer. Why would we want give
    > non-frozen tasks that are actually getting work done a preference over a
    > task that is frozen and doing absolutely nothing? It seems like that's
    > backwards and that we'd actually prefer killing the task doing nothing so
    > it can free its memory.

    I agree with David.
    Why don't you set oom_score_adj as -1000 for processes which never should die ?
    You don't freeze processes via user-land using cgroup ?


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