On Tue, 12 Sep 2017, Roman Gushchin wrote: > > I can't imagine that Tejun would be happy with a new mount option, > > especially when it's not required. > > > > OOM behavior does not need to be defined at mount time and for the entire > > hierarchy. It's possible to very easily implement a tunable as part of > > mem cgroup that is propagated to descendants and controls the oom scoring > > behavior for that hierarchy. It does not need to be system wide and > > affect scoring of all processes based on which mem cgroup they are > > attached to at any given time. > > No, I don't think that mixing per-cgroup and per-process OOM selection > algorithms is a good idea. > > So, there are 3 reasonable options: > 1) boot option > 2) sysctl > 3) cgroup mount option > > I believe, 3) is better, because it allows changing the behavior dynamically, > and explicitly depends on v2 (what sysctl lacks). > > So, the only question is should it be opt-in or opt-out option. > Personally, I would prefer opt-out, but Michal has a very strong opinion here. >
If it absolutely must be a mount option, then I would agree it should be opt-in so that it's known what is being changed rather than changing how selection was done in the past and requiring legacy users to now mount in a new way. I'd be interested to hear Tejun's comments, however, about whether we want to add controller specific mount options like this instead of a tunable at the root level, for instance, that controls victim selection and would be isolated to the memory cgroup controller as opposed to polluting mount options. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
