Hello, On Thu, Feb 13, 2020 at 05:36:36PM +0100, Michal Hocko wrote: > AFAIK systemd already offers knobs to configure resource controls [1]. Yes, it can set up the control knobs as directed but it doesn't ship with any material resource configurations or has conventions set up around it. > Besides that we are talking about memcg features which are available only > unified hieararchy and that is what systemd is using already. I'm not quite sure what the above sentence is trying to say. > > You gotta > > change the layout to configure resource control no matter what and > > it's pretty easy to do. systemd folks are planning to integrate higher > > level resource control features, so my expectation is that the default > > layout is gonna change as it develops. > > Do you have any pointers to those discussions? I am not really following > systemd development. There's a plan to integrate streamlined implementation of oomd into systemd. There was a thread somewhere but the only thing I can find now is a phoronix link. https://www.phoronix.com/scan.php?page=news_item&px=Systemd-Facebook-OOMD systemd recently implemented DisableControllers so that upper level slices can have authority over what controllers are enabled below it and in a similar vein there were discussions over making it auto-propagate some of the configs down the hierarchy but kernel doing the right thing and maintaining consistent semantics across controllers seems to be the right approach. There was also a discussion with a distro. Nothing concrete yet but I think we're more likely to see more resource control configs being deployed by default in the future. > Anyway, I am skeptical that systemd can do anything much more clever > than placing cgroups with a resource control under the root cgroup. At > least not without some tagging which workloads are somehow related. Yeah, exactly, all it needs to do is placing scopes / services according to resource hierarchy and configure overall policy at higher level slices, which is exactly what the memory.low semantics change will allow. > That being said, I do not really blame systemd here. We are not making > their life particularly easy TBH. Do you mind elaborating a bit? Thanks. -- tejun
