Re: [PATCH 1/1] Memory usage limit notification addition to memcg

[Balbir Singh <balbir@linux.vnet.ibm.com>]

* Dan Malek <dan@embeddedalley.com> [2009-07-16 11:16:29]:

> 
> On Jul 16, 2009, at 10:15 AM, Balbir Singh wrote:
> 
> > Dan, if you are suggesting that we incrementally add features, I
> > completely agree with you, that way the code is reviewable and
> > maintainable. As we add features we need to
> 
> Right, this is all goodness.  My specific comments are this patch
> adds a new useful feature and it's been through a couple of iterations
> to make it more acceptable.  Let's post it, as it makes people aware
> of such a feature since it's currently in use and useful, and then
> continue the discussion about how to make it (and all of the cgroup
> features) better.  Otherwise, this is going to degenerate into a "do
> everything but nothing gets done" ongoing discussion and I'll
> quickly lose interest and move on the something else :-)
> 
> There are currently two discussions in progress.  One is about
> notification limits, which this feature patch adds.  We need to
> close this discussion with a more feature rich implementation
> that addresses both upper and lower notification, the semantics
> of this feature in a cgroup hierarchy, and in particular the
> behavior outside of the memory controller group.
> 
> The second discussion is about event delivery in cgroups.
> Linux already has many mechanisms, and some product
> implementations patch even more of their own into the kernel.
> Outside of these implementation details, we have to determine
> what is useful for a cgroup.  Are events just arbitrary (anything
> can send any kind of event)?  How do we pass  information?
> Is there some standard header?  How do we control this so
> the event target is identified and we prevent event floods?
> And many more.....
>

I think you keep missing my pointers to cgroupstats - a genetlink
based mechanism for event delivery and request/response applications.

 
> > 1. Look at reuse
> > 2. Make sure the design is sane and will not prohibit further
> > development.
> 
> 3. Contain the scope of work so I can do it without affecting
>      the work that pays my salary :-)
>

Not at the cost of (1) and (2) and a patient discussion around what is
being proposed. 

-- 
	Balbir