[Devel] Re: [ckrm-tech] [PATCH] BC: resource beancounters (v4) (added user memory)

[Srivatsa Vaddagiri]

On Tue, Sep 12, 2006 at 10:22:32AM -0700, Rohit Seth wrote:
> On Tue, 2006-09-12 at 16:14 +0530, Srivatsa Vaddagiri wrote:
> > On Mon, Sep 11, 2006 at 12:10:31PM -0700, Rohit Seth wrote:
> > > It seems that a single notion of limit should suffice, and that limit
> > > should more be treated as something beyond which that resource
> > > consumption in the container will be throttled/not_allowed.
> > 
> > The big question is : are containers/RG allowed to use *upto* their
> > limit always? In other words, will you typically setup limits such that
> > sum of all limits = max resource capacity? 
> > 
> 
> If a user is really interested in ensuring that all scheduled jobs (or
> containers) get what they have asked for (guarantees) then making the
> sum of all container limits equal to total system limit is the right
> thing to do.
> 
> > If it is setup like that, then what you are considering as limit is
> > actually guar no?
> > 
> Right.  And if we do it like this then it is up to sysadmin to configure
> the thing right without adding additional logic in kernel.

Perhaps calling it as "limit" in confusing then (otoh it may go down well
with Linus!). I perhaps agree we need to go with one for now (in the
interest of making some progress), but we probably will come back to
this at a later point. For ex, I chanced upon this document:

	www.vmware.com/pdf/vmware_drs_wp.pdf

which explains how supporting a hard limit (in contrast to guar as we
have been discussing) can be usefull sometimes.

-- 
Regards,
vatsa