Re: [RFC/RFT PATCH v3] sched: automated per tty task groups

[Paul Menage <menage@google.com>]

On Tue, Nov 16, 2010 at 4:58 AM, Mike Galbraith <efault@gmx.de> wrote:
>
> A tasty alternative would be to have autogroup be it's own subsystem,
> with full cgroup userspace visibility/tweakability.

What exactly do you envisage by that? Having autogroup (in its current
incarnation) be a subsystem wouldn't really make sense - there's
already a cgroup subsystem for partitioning CPU scheduler groups. If
autogroups were integrated with cgroups I think that it would be as a
way of automatically creating (and destroying?) groups based on tty
connectedness.

We tried something like this with the ns subsystem, which would
create/enter a new cgroup whenever a new namespace was created; in the
end it turned out to be more of a nuisance than anything else.

People have proposed all sorts of in-kernel approaches for
auto-creation of cgroups based on things like userid, process name,
now tty, etc.

The previous effort for kernel process grouping (CKRM) started off
with a complex in-kernel rules engine that was ultimately dropped and
moved to userspace. My feeling is that userspace is a better place for
this - as Lennart pointed out, you can get a similar effect with a few
lines tweaking in a bash login script or a pam module that's much more
configurable from userspace and keeps all the existing cgroup stats
available.

Paul