Hey, On Mon, Mar 10, 2014 at 02:17:21PM +0000, Glyn Normington wrote: > Then we missed how to create a hierarchy with no associated > subsystems. The only way I can think of is to use mount, specify no > subsystems on -o (which defaults to all the subsystems defined in > the kernel), and run it in a kernel with no subsystems defined > (which seems unlikely these days). > > Is that what you had in mind or is there some other way of creating > a hierarchy with no subsystems attached?
Hierarchy name should be specified "-o name=" for hierarchies w/o any controllers. > >>Clarify that subsystems may be attached to multiple hierarchies, > >>although this isn't very useful, and explain what happens. > >And a subsystem may only be attached to a single hierarchy. > > Perhaps that's what should happen, but the following experiment > demonstrates a subsystem being attached to two hierarchies: > > $ pwd > /home/vagrant > $ mkdir mem1 > $ mkdir mem2 > $ sudo su > # mount -t cgroup -o memory none /home/vagrant/mem1 > # mount -t cgroup -o memory none /home/vagrant/mem2 > # cd mem1 > # mkdir inst1 > # ls inst1 > cgroup.clone_children memory.failcnt ... > # ls ../mem2 > cgroup.clone_children inst1 memory.limit_in_bytes ... > # cd inst1 > # echo 1000000 > memory.limit_in_bytes > # cat memory.limit_in_bytes > 1003520 > # cat ../../mem2/inst1/memory.limit_in_bytes > 1003520 > # echo $$ > tasks > # cat tasks > 1365 > 1409 > # cat ../../mem2/inst1/tasks > 1365 > 1411 You're mounting the same hierarchy twice. Those are two views into the same hierarchy. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
