On Tue, 24 Apr 2012, Glauber Costa wrote: > > Yes, for user memory, I see charging to p->mm->owner as allowing that > > process to eventually move and be charged to a different memcg and there's > > no way to do proper accounting if the charge is split amongst different > > memcgs because of thread membership to a set of memcgs. This is > > consistent with charges for shared memory being moved when a thread > > mapping it moves to a new memcg, as well. > > But that's the problem. > > When we are dealing with kernel memory, we are allocating a whole slab page. > It is essentially impossible to track, given a page, which task allocated > which object. > Right, so you have to make the distinction that slab charges cannot be migrated by memory.move_charge_at_immigrate (and it's not even specified to do anything beyond user pages in Documentation/cgroups/memory.txt), but it would be consistent to charge the same memcg for a process's slab allocations as the process's user allocations. My response was why we shouldn't be charging user pages to mem_cgroup_from_task(current) rather than mem_cgroup_from_task(current->mm->owner) which is what is currently implemented. If that can't be changed so that we can still migrate user memory amongst memcgs for memory.move_charge_at_immigrate, then it seems consistent to have all allocations done by a task to be charged to the same memcg. Hence, I suggested current->mm->owner for slab charging as well. -- 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
