On Tue, Jul 08, 2014 at 05:53:51PM -0400, Tejun Heo wrote: > Hello, Vivek. > > On Tue, Jul 08, 2014 at 03:42:26PM -0400, Vivek Goyal wrote: > > I have couple questions about new semantics. Following is my > > understanding. Is it right? > > > > - So after this change one can not use blkio controller on unified > > hiearchy if memory controller is mounted on some other hierarchy > > and is not available for mounting unified hiearchy. > > Hmmm? No, the only behavior which changes is when both blkcg and > memcg are mounted on the unified hierarchy. Nothing else changes. > The dependency behavior kicks in iff memcg is available on the unified > hierarchy. Ok, good to know that dependency kicks in only if controlle being depended on is available on the hierarchy. > > > - If blkio controller is enabled on unified hiearchy (memory controller > > implicitly enabled), then one can't mount memory controller on other > > hierarchies without first disabling blkio controller on unified hiearchy. > > Yes, blkio needs to be disabled to the root for memcg to be able to > become free. This is an extra restriction but I don't think it's > anything drastic. Once a controller starts being actively used on any > hierarchy, nothing has been guaranteed about when the controller would > become free again even if the whole hierarchy is reduced to the root. Agreed. Thanks for the clarification. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
