On Fri 26-02-21 08:42:29, Yang Shi wrote: > On Thu, Feb 25, 2021 at 11:30 PM Michal Hocko <mhocko@xxxxxxxx> wrote: > > > > On Thu 25-02-21 18:12:54, Yang Shi wrote: > > > When debugging an oom issue, I found the oom_kill counter of memcg is > > > confusing. At the first glance without checking document, I thought it > > > just counts for memcg oom, but it turns out it counts both global and > > > memcg oom. > > > > Yes, this is the case indeed. The point of the counter was to count oom > > victims from the memcg rather than matching that to the source of the > > oom. Rememeber that this could have been a memcg oom up in the > > hierarchy as well. Counting victims on the oom origin could be equally > > Yes, it is updated hierarchically on v2, but not on v1. I'm supposed > this is because v1 may work in non-hierarchcal mode? If this is the > only reason we may be able to remove this to get aligned with v2 since > non-hierarchal mode is no longer supported. I believe the reson is that v1 can have tasks in the intermediate (non-leaf) memcgs. So you wouldn't have a way to tell whether the oom kill has happened in such a memcg or somewhere down the hierarchy. -- Michal Hocko SUSE Labs
