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

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

On Thu, 10 Feb 2011 09:26:08 +0800
Li Zefan <lizf@cn.fujitsu.com> wrote:

> jacob pan wrote:
> > 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?
> > 
> 
> You're right. I made a mistake when looking into the patch.
> 
> btw, I made a few other comments in your code, that you may have
> overlooked.
sorry, I missed them.