Re: [PATCHSET] cgroup: cftype based file interface, take #2

From: Tejun Heo
Date: Fri Mar 30 2012 - 11:42:53 EST

Hey, Li.

On Fri, Mar 30, 2012 at 08:42:07PM +0800, Li Zefan wrote:
> > This patch replaces cgroup file interface with cftype based one which
> > allows dynamic additions and removals of cftype arrays whether the
> > target subsystem is attached or not. This can be used to make subsys
> > rebinding via remount work properly but I intentionally avoided doing
> > that at the moment.
> What's the problem with remount?

Subsys can't be changed if any non-root cgroup exists.

> and is it important enough that it should be fixed even the feature
> is marked as deprecated?

I'm not sure. We *might* need it during multi-mount -> single-mount
transition depending on how that's implemented, so the "at the moment"
qualifier. It probably won't be fixed but I'm not fully sure.

> > This makes cgroup population simpler for controllers and will be used
> > to allow controllers to be more dynamic. e.g. blkio subsys has
> > sub-policies which may come and go while blkio subsys is attached and
> > it currently uses fixed set of files which stays blank if not in use.
> Dynamic cgroup files was mentioned before. The scenario in mind was blkio
> control files can be added/removed automatically as devices come and ago.
> So this time blkio subsystem is really going to be made more dynamic
> soon?

Patchset already posted.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at