Re: [PATCH] cgroupfs: create /sys/fs/cgroup to mount cgroupfs on

[Greg KH <gregkh@suse.de>]

On Thu, Jul 22, 2010 at 11:44:50AM -0700, Paul Menage wrote:
> On Thu, Jul 22, 2010 at 11:36 AM, Greg KH <gregkh@suse.de> wrote:
> >
> > Really?  I see systems mounting it at /cgroups/ in the filesystem today.
> 
> Sure, it *can* be mounted as a single instance, but you then lose
> flexibility. E.g. at Google we want to have a different hierarchy for
> the CPU subsystem (with the tree grouped according to
> latency-sensitive versus batch, etc) and memory (grouped according to
> what jobs are sharing memory with each other).
> 
> > Where are you expecting it to be mounted at?
> 
> I have no particular expectation. (At Google we're actually using
> /dev/cgroup/* but that's just for historical reasons, from
> /dev/cpuset). Under /sys/fs/cgroup sounds reasonable, but you'd want
> people to have the ability to manually create subdirs in there for
> separate mount points.

Ok, that's great, but it's not where the distros are starting to mount
it at.  As I learned with debugfs, you need to pick a location for
people to mount it at, otherwise it ends up all over the place.

If you are using /dev/cgroup/ that's nice, but I don't think that people
are expecting a whole filesystem under a /dev/ subdirectory.

I didn't realize that cgroupfs had so many different options that would
enable it to handle multiple mounts in this way.

Hm, Lennart, Kay, any ideas as to where to put it in a "standard" way?

thanks,

greg k-h