On Thursday 22 January 2009 10:57:21 KAMEZAWA Hiroyuki wrote: > On Thu, 22 Jan 2009 10:43:12 +0530 > > Nikanth Karthikesan <knikanth@xxxxxxx> wrote: > > On Thursday 22 January 2009 08:58:43 KAMEZAWA Hiroyuki wrote: > > > On Wed, 21 Jan 2009 16:38:21 +0530 > > > > > > Nikanth Karthikesan <knikanth@xxxxxxx> wrote: > > > > As Alan Cox suggested/wondered in this thread, > > > > http://lkml.org/lkml/2009/1/12/235 , 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. > > > > > > > > Signed-off-by: Nikanth Karthikesan <knikanth@xxxxxxx> > > > > > > Assume following > > > - the usar can tell "which process should be killed at first" > > > > > > What is the difference between oom_adj and this cgroup to users ? > > > > It is next to impossible to specify the order among say 10 memory hogging > > tasks using oom_adj. Using this oom-controller users can specify the > > exact order. > > > > > If oom_adj is hard to use, making it simpler is a good way, I think. > > > rather than adding new complication. > > > > > > It seems both of oom_adj and this cgroup will be hard-to-use functions > > > for usual system administrators. But no better idea than using memcg > > > and committing memory usage. > > > > To use oom_adj effectively one should continuously monitor oom_score of > > all the processes, which is a complex moving target and keep on adjusting > > the oom_adj of many tasks which still cannot guarantee the order. This > > controller is deterministic and hence easier to use. > > Okay, thank you for explanation :) > I think it's better to explain "why this is much easier to use rather > than oom_adj and what is the benefit to users." in your patch description > and to improve your documentation. > > +But it is very difficult to suggest an order among tasks to be killed > during +Out Of Memory situation. The OOM Killer controller aids in doing > that. > > As. > Difference from oom_adj: > This allows users to specify "strict order" of oom-kill's > select-bad-process operation. While oom_adj just works as a hint for the > kernel, OOM Killer Controller gives users full control. > > In general, it's very hard to specify oom-kill order of several > applications only by oom_adj because it's just affects "badness" > calculation. > Yes, this could be added to the patch description or the documentation. Thanks Nikanth _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers