Re: [PATCH 1/1, v7] cgroup/freezer: add per freezer duty ratio control

[Arjan van de Ven <arjan@linux.intel.com>]

On 2/13/2011 4:44 PM, KAMEZAWA Hiroyuki wrote:
> On Sat, 12 Feb 2011 15:29:07 -0800
> Matt Helsley<matthltc@us.ibm.com>  wrote:
>
>> On Fri, Feb 11, 2011 at 11:10:44AM -0800, 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
>> Again: I don't think this is the right approach in the long term.
>> It would be better not to add this interface and instead enable the
>> cpu cgroup subsystem for non-rt tasks using a similar duty ratio
>> concept..
>>
>> Nevertheless, I've added some feedback on the code for you here :).
>>
> AFAIK, there was a work for bandwidth control in CFS.
>
> http://linux.derkeiler.com/Mailing-Lists/Kernel/2010-10/msg04335.html
>
> I tested this and worked fine. This schduler approach seems better for
> my purpose to limit bandwidth of apprications rather than freezer.

for our purpose, it's not about bandwidth.
it's about making sure the class of apps don't run for a long period 
(30-second range) of time.