On Tue, 27 Jan 2009, KOSAKI Motohiro wrote: > Confused. > > As far as I know, people want the method of flexible cache treating. > but oom seems less flexible than userland notification. > > Why do you think notification is bad? > There're a couple of proposals that have been discussed recently that share some functional behavior. One is the cgroup oom notifier that allows you to attach a task to wait on an oom condition for a collection of tasks. That allows userspace to respond to the condition by droping caches, adding nodes to a cpuset, elevating memory controller limits, sending a signal, etc. It can also defer to the kernel oom killer as a last resort. The other is /dev/mem_notify that allows you to poll() on a device file and be informed of low memory events. This can include the cgroup oom notifier behavior when a collection of tasks is completely out of memory, but can also warn when such a condition may be imminent. I suggested that this be implemented as a client of cgroups so that different handlers can be responsible for different aggregates of tasks. I think the latter is a much more powerful tool and includes all the behavior of the former. It preserves the oom killer as a last resort for the kernel and defers all preference killing or lowmem responses to userspace. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers