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

From: jacob pan
Date: Wed Feb 09 2011 - 13:16:36 EST


On Wed, 09 Feb 2011 11:07:59 +0800
Li Zefan <lizf@xxxxxxxxxxxxxx> wrote:

> jacob.jun.pan@xxxxxxxxxxxxxxx wrote:
> > From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> >
> > 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?
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