On Fri, 12 Mar 2010, KAMEZAWA Hiroyuki wrote: > One question. Assume a host A and B. A has 4G memory, B has 8G memory. > > Here, an applicaton which consumes 2G memory. > > Then, this application's oom_score will be 500 on A, 250 on B. > Right. > How admin detemine the best oom_score_adj value ? Does it depend on envrionment > even if runnning the same application ? > Yes, because the idea of /proc/pid/oom_score_adj is to allow userspace to both set priorities for oom killing and also define when a task has become a memory leaker (i.e. using far more memory than expected). You can't use a quantity of memory to either prefer or bias an application because you don't know its memory usage in context of the system, memcg, mempolicy, or cpuset: a bias of 1G would mean "always kill this task" in a cpuset with a 512MB node whereas it would mean relatively nothing on a 64GB machine. With a proportion, however, you could easily set a oom_score_adj of 250, for example, to say this application should be penalized 25% of available memory regardless of whether that's the entire system or a "virtual system" consisting of a cpuset, memcg, or mempolicy. It would obviously be trivial to add another /proc/pid knob that would calculate the value for you given a quantity based on the memory constraints of pid, I'm not against that addition. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>