Hello, Michal. On Tue, Sep 10, 2019 at 01:54:48PM +0200, Michal Hocko wrote: > > So, while it'd great to have shrinkers in the longer term, it's not a > > strict requirement to be accounted in memcg. It already accounts a > > lot of memory which isn't reclaimable (a lot of slabs and socket > > buffer). > > Yeah, having a shrinker is preferred but the memory should better be > reclaimable in some form. If not by any other means then at least bound > to a user process context so that it goes away with a task being killed > by the OOM killer. If that is not the case then we cannot really charge > it because then the memcg controller is of no use. We can tolerate it to > some degree if the amount of memory charged like that is negligible to > the overall size. But from the discussion it seems that these buffers > are really large. Yeah, oom kills should be able to reduce the usage; however, please note that tmpfs, among other things, can already escape this restriction and we can have cgroups which are over max and empty. It's obviously not ideal but the system doesn't melt down from it either. Thanks. -- tejun
