Re: [RFC] Mount point suggestions for cgroup

[Jan Safranek <jsafrane@redhat.com>]

On 11/04/2009 05:11 PM, Serge E. Hallyn wrote:
> Quoting Dave Hansen (dave@linux.vnet.ibm.com):
>> On Wed, 2009-11-04 at 13:46 +0530, Balbir Singh wrote:
>>> The reason I liked /dev/cgroup was because cpusets could be
>>> mounted at /dev/cpuset or /dev/cgroup/cpuset. My concern with /cgroup
>>> is that a ls "/" now becomes larger in size. But I'll take your vote
>>> for it as +1 for /cgroup.
>>
>> /dev/pts is a decent precedent for doing it under /dev, although it does
>> deal with actual devices.  cgroups do not.
>
> Hmm, on whose behalf are you making this decision?
>
> LSB people will want to avoid using /cgroup,

LSB (and FHS) IMHO does not specify any place for such stuff:

/dev - for devices only, cgroups are not devices
/mnt - for admin temporary mounts and "should not affect the manner in 
which any program is run"
/var - for "any unsorted variable data", cgroups are not "unsorted 
variable data", it's interface to kernel

FHS does not specify either /sys and /selinux and it seems to me nobody 
complains about them.

/sys/cgroup would be the best, if sysfs supported mkdir(). But it does 
not :(. Our kernel guys told me it's relatively easy to create new empty 
directory /sys/cgroup (or /sys/kernel/cgroup), but it must be compiled 
into kernel or a module. Then I could mount some tmpfs to it, create 
/sys/cgroup/cpu, /sys/cgroup/memory etc. and mount the control group 
hierarchies there... but as you can see, it's really really ugly thing 
to do.

Jan