On Thursday 22 January 2009 02:19:50 David Rientjes wrote: > On Wed, 21 Jan 2009, Nikanth Karthikesan wrote: > > This is a container group based approach to override the oom killer > > selection without losing all the benefits of the current oom killer > > heuristics and oom_adj interface. > > > > It adds a tunable oom.victim to the oom cgroup. The oom killer will kill > > the process using the usual badness value but only within the cgroup with > > the maximum value for oom.victim before killing any process from a cgroup > > with a lesser oom.victim number. Oom killing could be disabled by setting > > oom.victim=0. > > This doesn't help in memcg or cpuset constrained oom conditions, which > still go through select_bad_process(). > > If the oom.victim value is high for a specific cgroup and a memory > controller oom occurs in a disjoint cgroup, for example, it's possible to > needlessly kill tasks. Obviously that is up to the administrator to > configure, but may not be his or her desire for system-wide oom > conditions. > > It may be preferred to kill tasks in a specific cgroup first when the > entire system is out of memory or kill tasks within a cgroup attached to a > memory controller when it is oom. > > The same scenario applies for cpuset-constrained ooms. Since oom.victim > is given higher preference than all tasks' oom_adj values, it is possible > to needlessly kill tasks that do not lead to future memory freeing for the > nodes attached to that cpuset. > > It also requires that you synchronize the oom.victim values amongst your > cgroups. No, this is not specific to memcg or cpuset cases alone. The same needless kills will take place even without memcg or cpuset when an administrator specifies a light memory consumer to be killed before a heavy memory user. But it is up to the administrator to use it wisely. We also provide a panic_on_oom option that an administrator could use, not just to kill few more tasks but all tasks in the system ;) Thanks Nikanth _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
