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Message-ID: <28c262360810261934g12aa6f15mbd133d39eb57b683@mail.gmail.com>
Date: Mon, 27 Oct 2008 11:34:34 +0900
From: "MinChan Kim" <minchan.kim@gmail.com>
To: "Dong-Jae Kang" <baramsori72@gmail.com>
Subject: Re: [Question] power management related with cgroup based resource management
Cc: "Paul Menage" <menage@google.com>, "Matthew Garrett" <mjg@redhat.com>,
       balbir@linux.vnet.ibm.com, xen-devel@lists.xensource.com,
       containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
       virtualization@lists.linux-foundation.org, dm-devel@redhat.com,
       corsetproject@googlegroups.com,
       "Vaidyanathan Srinivasan" <svaidy@linux.vnet.ibm.com>
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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
--
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