>> > + if (memcg_has_children(iter)) >> > + continue; >> >> && iter != root_mem_cgroup ? > > Oh, sure. I had a stupid bug in my test script, which prevented me from > catching this. Thanks! > > This should fix the problem. > -- > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 2e82625bd354..b3848bce4c86 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2807,7 +2807,8 @@ static void select_victim_memcg(struct mem_cgroup *root, struct oom_control *oc) > * We don't consider non-leaf non-oom_group memory cgroups > * as OOM victims. > */ > - if (memcg_has_children(iter) && !mem_cgroup_oom_group(iter)) > + if (memcg_has_children(iter) && iter != root_mem_cgroup && > + !mem_cgroup_oom_group(iter)) > continue; I think you are mixing the 3rd and 4th patch. The root_mem_cgroup check should be in 3rd while oom_group stuff should be in 4th. >> >> Shouldn't there be a CSS_ONLINE check? Also instead of css_get at the >> end why not css_tryget_online() here and css_put for the previous >> selected one. > > Hm, why do we need to check this? I do not see, how we can choose > an OFFLINE memcg as a victim, tbh. Please, explain the problem. > Sorry about the confusion. There are two things. First, should we do a css_get on the newly selected memcg within the for loop when we still have a reference to it? Second, for the OFFLINE memcg, you are right oom_evaluate_memcg() will return 0 for offlined memcgs. Maybe no need to call oom_evaluate_memcg() for offlined memcgs. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
