Re: [RFC, PATCH 0/5] Going forward with Resource Management - A cpu controller

[Nick Piggin <nickpiggin@yahoo.com.au>]

Andrew Morton wrote:
> On Fri, 4 Aug 2006 10:37:53 +0530
> Srivatsa Vaddagiri <vatsa@in.ibm.com> wrote:
> 
> 
>>Resource management has been talked about quite extensively in the
>>past, more recently in the context of containers. The basic requirement
>>here is to provide isolation between *groups* of task wrt their use
>>of various resources like CPU, Memory, I/O bandwidth, open file-descriptors etc.
>>
>>Different maintainers have however expressed different opinions over the need to
>>complicate the kernel to meet this need, especially since it involves core 
>>kernel code like the resource schedulers. 
>>
>>A BoF was hence held at OLS this year to come to a consensus on the minimum 
>>requirements of a resource management solution for Linux kernel. Some notes 
>>taken at the BoF are posted here:
>>
>>	http://www.uwsg.indiana.edu/hypermail/linux/kernel/0607.3/0896.html
>>
>>An important consensus point of the BoF seemed to be "focus on real 
>>controllers more, preferably memory first, using some simple interface
>>and task grouping mechanism".
> 
> 
> ug, I didn't know this.  Had I been there (sorry) I'd have disagreed with
> this whole strategy.
> 
> I thought the most recently posted CKRM core was a fine piece of code.  It
> provides the machinery for grouping tasks together and the machinery for
> establishing and viewing those groupings via configfs, and other such
> common functionality.  My 20-minute impression was that this code was an
> easy merge and it was just awaiting some useful controllers to come along.
> 
> And now we've dumped the good infrastructure and instead we've contentrated
> on the controller, wired up via some imaginative ab^H^Hreuse of the cpuset
> layer.
> 
> I wonder how many of the consensus-makers were familiar with the
> contemporary CKRM core?

Sorry, I've been busy with offline stuff and won't be able to catch up with
emails until next week -- someone else might have already covered this.

But: I think we definitely agreed that a nice simple implementation and even
userspace API for grouping tasks would be a no-brainer.

I advocated implementing some simple controllers on top of such an interface
first, that people can start to put in some of their requirements, see if a
common controller framework should be created, look at what interfaces people
want for them.

I don't have a problem with CKRM as such, but I think there are other groups
with good approaches and the problem has been to get people working together.

-- 
SUSE Labs, Novell Inc.
Send instant messages to your online friends http://au.messenger.yahoo.com