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> > > > delta *= 4; > > > > do_div(delta, shrinker->seeks); > > > > > > > > The problem is that on a default priority (which is 12) no pressure > > > > is applied at all, if the number of potentially reclaimable objects > > > > is less than 4096 (1<<12). > > > > > > > > This causes the last objects on slab caches of no longer used cgroups > > > > to never get reclaimed, resulting in dead cgroups staying around forever. > > > > > > But this problem pertains to all types of objects, not just the cgroup > > > cache, yes? > > > > Well, of course, but there is a dramatic difference in size. > > > > Most of these objects are taking few hundreds bytes (or less), > > while a memcg can take few hundred kilobytes on a modern multi-CPU > > machine. Mostly due to per-cpu stats and events counters. > > > > Beside memcg, all of its kmem caches, most empty, are stuck in memory > as well. For SLAB even the memory overhead of an empty kmem cache is > not negligible. Right! I mean the main part of the problem is not in these 4k (mostly vfs-cache related) objects themselves, but in objects, which are referenced by these 4k objects. Thanks!