Quoting Glauber Costa (glommer@xxxxxxxxxxxxx): > >>The support for multiple process hierarchies always struck me as > >>rather strange. If you forget about the current cgroup controllers > >>and their implementations, the *only* reason to support multiple > >>hierarchies is if you want to apply resource limits based on different > >>orthogonal categorizations. > >> Right, the old lwn writeup took the same approach: http://lwn.net/Articles/236038/ > >>Documentation/cgroups.txt seems to be written with this consideration > >>on mind. It's giving an example of applying limits accoring to two > >>orthogonal categorizations - user groups (profressors, students...) > >>and applications (WWW, NFS...). While it may sound like a valid use > >>case, I'm very skeptical how useful or common mixing such orthogonal > >>categorizations in a single setup would be. My first inclination is to agree, but counterexamples do come to mind. I could imagine a site saying "users can run (X) (say, ftpds), but the memory consumed by all those ftpds must not be > 10% total RAM". At the same time, they may run several apaches but want them all locked to two of the cpus. It might be worth a formal description of the new limits on use cases such changes (both dropping support for orthogonal cgroups, and limiting cgroups hierarchies to a mirror pstrees, separately) would bring. To me personally the hierarchy limitation is more worrying. There have been times when I've simply created cgroups for 'compile' and 'image build', with particular cpu and memory limits. If I started a second simultaneous compile, I'd want both compiles confined together. (That's not to say the simplification might not be worth it, just bringing up the other side) -serge _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/containers
