On Tue, Dec 19, 2017 at 9:33 AM, Tejun Heo <tj@xxxxxxxxxx> wrote: > Hello, > > On Tue, Dec 19, 2017 at 09:23:29AM -0800, Shakeel Butt wrote: >> To provide consistent memory usage history using the current >> cgroup-v2's 'swap' interface, an additional metric expressing the >> intersection of memory and swap has to be exposed. Basically memsw is >> the union of memory and swap. So, if that additional metric can be > > Exposing anonymous pages with swap backing sounds pretty trivial. > >> used to find the union. However for consistent memory limit >> enforcement, I don't think there is an easy way to use current 'swap' >> interface. > > Can you please go into details on why this is important? I get that > you can't do it as easily w/o memsw but I don't understand why this is > a critical feature. Why is that? > Making the runtime environment, an invariant is very critical to make the management of a job easier whose instances run on different clusters across the world. Some clusters might have different type of swaps installed while some might not have one at all and the availability of the swap can be dynamic (i.e. swap medium outage). So, if users want to run multiple instances of a job across multiple clusters, they should be able to specify the limits of their jobs irrespective of the knowledge of cluster. The best case would be they just submits their jobs without any config and the system figures out the right limit and enforce that. And to figure out the right limit and enforcing it, the consistent memory usage history and consistent memory limit enforcement is very critical. thanks, Shakeel -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
