On Fri, 2009-03-20 at 17:26 -0400, Oren Laadan wrote: > Dave Hansen wrote: > > On Fri, 2009-03-20 at 16:48 -0400, Oren Laadan wrote: > >> Does that scale well with many (1000's) of tasks ? > >> > >> (The motivation to expose 'nsproxy_objref' to user space was to allow > >> user-space to decide on a sequence of clones/unshared that will create > >> an equivalent process tree with space-efficient nsproxy's). > > > > OK, so you're saying that there's no way for userspace to tell that a > > set of tasks share an nsproxy other than exporting that nsproxy? > > I don't think so. Maybe the namespaces people know better. Please go look at the code. Two processes share an nsproxy (or *can* share an nsproxy) when all of the namespace pointers are the same. After allocation and initialization, we basically don't ever write to the nsproxy. We just hook it into a task and run with it. If anything ever unshares one of the nsproxy namespaces, before writing to it we *first* create a new nsproxy which is a copy of the old one. We basically open-code copy-on-write semantics for the nsproxy. This means that it is safe for any two tasks that share all of the pointers in the nsproxy to share an nsproxy itself. -- Dave _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
