2008-10-21 02:54:42

by Dong-Jae Kang

[permalink] [raw]
Subject: [Question] power management related with cgroup based resource management

Hi, all

These days, I am interested in green IT area for low power OS
So, I have a question about it.
Is there any good idea or comments about power management related with
cgroup based resource management?
I have no idea about that, but it seems to be possible to find a good concept.
And I hope so
Is it some strange question? ^^

Regards,
Dong-Jae Kang


2008-10-24 11:47:32

by Balbir Singh

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

Dong-Jae Kang wrote:
> Hi, all
>
> These days, I am interested in green IT area for low power OS
> So, I have a question about it.
> Is there any good idea or comments about power management related with
> cgroup based resource management?
> I have no idea about that, but it seems to be possible to find a good concept.
> And I hope so
> Is it some strange question? ^^

lesswatts.org, linux-pm (mailing list) are good sources on Power Management. I
would recommend asking at those mailing lists (there are several new features
like range timers, no idle hertz, sched_mc consolidation and much more). Could
you be specific about what you are looking for? Are you looking at
Server/Desktop power management?

--
Balbir

2008-10-24 12:24:32

by Dong-Jae Kang

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

Hi, Balbir Singh

2008/10/24 Balbir Singh <[email protected]>:
> Dong-Jae Kang wrote:
>> Hi, all
>>
>> These days, I am interested in green IT area for low power OS
>> So, I have a question about it.
>> Is there any good idea or comments about power management related with
>> cgroup based resource management?
>> I have no idea about that, but it seems to be possible to find a good concept.
>> And I hope so
>> Is it some strange question? ^^
>
> lesswatts.org, linux-pm (mailing list) are good sources on Power Management. I
> would recommend asking at those mailing lists (there are several new features
> like range timers, no idle hertz, sched_mc consolidation and much more). Could
> you be specific about what you are looking for? Are you looking at
> Server/Desktop power management?
>

Thank you very much for your kind recommendation.^^
this site information will be helpful for me.
As your recommendation, I will try to contact to lesswatts.org,
linux-pm (mailing list)

I am interested in power management in server side.
and I just wonder this question, "Is there any related point between
cgroup framework and power management?"

Thanks again

Regards,
Dong-Jae Kang

2008-10-24 23:25:27

by Matthew Garrett

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

On Fri, Oct 24, 2008 at 09:24:21PM +0900, Dong-Jae Kang wrote:

> I am interested in power management in server side.
> and I just wonder this question, "Is there any related point between
> cgroup framework and power management?"

Not currently, though it would certainly be possible to use cgroups as a
mechanism for providing application-specific power management.

--
Matthew Garrett | [email protected]

2008-10-25 08:06:06

by Dong-Jae Kang

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

Thank you for your positive opinion about my question

I also hope cgroup framework has good point related with power management
I think I need more re-consideration for it. ^^

How do you think about cgroup based management of new HW devices, for
example, SSD, NVRAM and so on.
Is there any requirement for it ?
and is there any required work for it?
I didn't seriously consider about that until now.^^ so I don't have cool idea
but, I think it is worthy to find new domain to be applied by existing
technology

thank you.

Best Regards,
Dong-Jae Kang

2008/10/25 Matthew Garrett <[email protected]>:
> On Fri, Oct 24, 2008 at 09:24:21PM +0900, Dong-Jae Kang wrote:
>
>> I am interested in power management in server side.
>> and I just wonder this question, "Is there any related point between
>> cgroup framework and power management?"
>
> Not currently, though it would certainly be possible to use cgroups as a
> mechanism for providing application-specific power management.
>
> --
> Matthew Garrett | [email protected]
>



--
-------------------------------------------------------------------------------------------------
DONG-JAE, KANG
Senior Member of Engineering Staff
Internet Platform Research Dept, S/W Content Research Lab
Electronics and Telecommunications Research Institute(ETRI)
138 Gajeongno, Yuseong-gu, Daejeon, 305-700 KOREA
Phone : 82-42-860-1561 Fax : 82-42-860-6699
Mobile : 82-10-9919-2353 E-mail : [email protected] (MSN)
-------------------------------------------------------------------------------------------------

2008-10-25 15:44:15

by Paul Menage

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

On Sat, Oct 25, 2008 at 1:05 AM, Dong-Jae Kang <[email protected]> wrote:
> Thank you for your positive opinion about my question
>
> I also hope cgroup framework has good point related with power management
> I think I need more re-consideration for it. ^^
>
> How do you think about cgroup based management of new HW devices, for
> example, SSD, NVRAM and so on.
> Is there any requirement for it ?
> and is there any required work for it?
> I didn't seriously consider about that until now.^^ so I don't have cool idea
> but, I think it is worthy to find new domain to be applied by existing
> technology

Control Groups is just a framework for associating state with
(user-created) groups of processes. So if you have a problem to solve
that involves tracking state for different processes, or applying
different behaviour to groups of processes based on that group's
state, then cgroups may well be an appropriate tool.

In the case you mention (management of new devices) that's already
somewhat covered by the existing device isolation subsystem - you can
create a cgroup that has (or doesn't have) access to particular HW
devices.

Paul

2008-10-26 07:54:57

by Dong-Jae Kang

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

Hi, Paul Menage

Thank you for your comments

> Control Groups is just a framework for associating state with
> (user-created) groups of processes. So if you have a problem to solve
> that involves tracking state for different processes, or applying
> different behaviour to groups of processes based on that group's
> state, then cgroups may well be an appropriate tool.
>
> In the case you mention (management of new devices) that's already
> somewhat covered by the existing device isolation subsystem - you can
> create a cgroup that has (or doesn't have) access to particular HW
> devices.
>
In some aspect, your opinion is right.
Existing controller(ex. disk IO controllers) can be run on new HW
devices(ex. SSD), existing block layer and so on.

but, what I mean is that such controllers can support more performance
if the controllers are rewrited with reconsideration of the features
of new HW devices. in other words, what I mean can be optimization of
controllers for new devices
For example,
In case of SSD, current IO scheduler layer is needed ? although i can
not sure about it ^^
or process sleep is needed after throwing the IO requests to storage ?
the role of page cache in SSD or NVRAM is less important than in
normal HDD and ....

I heard that many research centers in comanies and universities have
studied about smiliar research
of course, it can be OS itself, device drivers, block layer, file
systems and memory management

Under this trend,
I just wonder whether the trend can be reflected to cgroup based
controllers or not.
and whether it is meaningful or not?
How do you think about this?
My opinion may be some humble ^^

Thank you
--
Best Regards,
Dong-Jae Kang

2008-10-26 08:21:50

by Paul Menage

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

On Sun, Oct 26, 2008 at 12:54 AM, Dong-Jae Kang <[email protected]> wrote:
>
> Under this trend,
> I just wonder whether the trend can be reflected to cgroup based
> controllers or not.

Potentially, but I'm not sure that anyone is looking at the kind of
thing that you're describing.

Feel free to post a design for it if you have some concrete ideas.

Paul

2008-10-27 02:34:45

by Minchan Kim

[permalink] [raw]
Subject: Re: [Question] power management related with cgroup based resource management

Hi, Dong-Jae.


> In some aspect, your opinion is right.
> Existing controller(ex. disk IO controllers) can be run on new HW
> devices(ex. SSD), existing block layer and so on.
>
> but, what I mean is that such controllers can support more performance
> if the controllers are rewrited with reconsideration of the features
> of new HW devices. in other words, what I mean can be optimization of
> controllers for new devices
> For example,
> In case of SSD, current IO scheduler layer is needed ? although i can
> not sure about it ^^
> or process sleep is needed after throwing the IO requests to storage ?
> the role of page cache in SSD or NVRAM is less important than in
> normal HDD and ....

What you mention is already included in 2.6.28 merge window.
I think we can use this feature on NVRAM, too.

http://lwn.net/Articles/303270/


> I heard that many research centers in comanies and universities have
> studied about smiliar research
> of course, it can be OS itself, device drivers, block layer, file
> systems and memory management
>
> Under this trend,
> I just wonder whether the trend can be reflected to cgroup based
> controllers or not.
> and whether it is meaningful or not?
> How do you think about this?
> My opinion may be some humble ^^

I think it's not cgroup controller's role but each subsystem's one.
As you can see above article, Many mainline guys try to improve
performance in each subsystems.

Do you have a scenario or idea how to use cgroup frame work to manage
devices like NVRAM, SSD ??

> Thank you
> --
> Best Regards,
> Dong-Jae Kang
> --
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--
Kinds regards,
MinChan Kim