Re: [PATCH 1/1, v6] cgroup/freezer: add per freezer duty ratio control

[jacob pan <jacob.jun.pan@linux.intel.com>]

On Wed, 09 Feb 2011 11:07:59 +0800
Li Zefan <lizf@cn.fujitsu.com> wrote:

> jacob.jun.pan@linux.intel.com wrote:
> > From: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > 
> > Freezer subsystem is used to manage batch jobs which can start
> > stop at the same time. However, sometime it is desirable to let
> > the kernel manage the freezer state automatically with a given
> > duty ratio.
> > For example, if we want to reduce the time that backgroup apps
> > are allowed to run we can put them into a freezer subsystem and
> > set the kernel to turn them THAWED/FROZEN at given duty ratio.
> > 
> > This patch introduces two file nodes under cgroup
> > freezer.duty_ratio_pct and freezer.period_sec
> > 
> > Usage example: set period to be 5 seconds and frozen duty ratio 90%
> > [root@localhost aoa]# echo 90 > freezer.duty_ratio_pct
> > [root@localhost aoa]# echo 5000 > freezer.period_ms
> > 
> 
> So after:
> 
> # echo FROZEN > freezer.state
> # echo 90 > freezer.duty_ratio_pct
> # echo 5000 > freezer.period_ms
> ...
> # echo 0 > freezer.duty_ratio_pct
> 
> All the tasks in this cgroup are in THAWED state, but the cgroup is
> in FROZEN state. This should be fixed.
I don't know how could this ever happen. Is it based on your testing?
Whenever tasks in a cgroup are thawed/frozen, its freezer state would
change accordingly.
After your example, freezer.state should have THAWED. It matches
user's intention, i.e. if a user do
echo 0 > freezer.duty_ratio_pct
It must want 0% to be frozen, which is THAWED.

Am I missing anything?