On Sat, Apr 3, 2021 at 3:17 AM Dan Schatzberg <schatzberg.dan@xxxxxxxxx> wrote: > > set_active_memcg() worked for kernel allocations but was silently > ignored for user pages. > > This patch establishes a precedence order for who gets charged: > > 1. If there is a memcg associated with the page already, that memcg is > charged. This happens during swapin. > > 2. If an explicit mm is passed, mm->memcg is charged. This happens > during page faults, which can be triggered in remote VMs (eg gup). > > 3. Otherwise consult the current process context. If there is an > active_memcg, use that. Otherwise, current->mm->memcg. > > Previously, if a NULL mm was passed to mem_cgroup_charge (case 3) it > would always charge the root cgroup. Now it looks up the active_memcg > first (falling back to charging the root cgroup if not set). > > Signed-off-by: Dan Schatzberg <schatzberg.dan@xxxxxxxxx> > Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Acked-by: Tejun Heo <tj@xxxxxxxxxx> > Acked-by: Chris Down <chris@xxxxxxxxxxxxxx> > Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Thanks.
