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

[Chandra Seetharaman]

On Wed, 2006-09-13 at 18:22 -0700, Rohit Seth wrote:
<snip>
> > 
> > Here are results of some of the benchmarks we have run in the past
> > (April 2005) with CKRM which showed no/negligible performance impact in
> > that scenario.
> > http://marc.theaimsgroup.com/?l=ckrm-tech&m=111325064322305&w=2
> > http://marc.theaimsgroup.com/?l=ckrm-tech&m=111385973226267&w=2
> > http://marc.theaimsgroup.com/?l=ckrm-tech&m=111291409731929&w=2
> > > 
> 
> 
> These are good results.  But I still think the cost will increase over a
> period of time as more logic gets added.  Any data on microbenchmarks

IMO, overhead may not increase for a _non-user_ of the feature.

> like lmbench.

I think we have run those, but I could not find the results in the
mailing list.
>  
> > <snip>
> > 
> > > > Not at all. If the container they are interested in is guaranteed, I do
> > > > not see how apps running outside a container would affect them.
> > > > 
> > > 
> > > Because the kernel (outside the container subsystem) doesn't know of
> > 
> > The core resource subsystem (VM subsystem for memory) would know about
> > the guarantees and don't cares, and it would handle it appropriately.
> > 
> 
> ...meaning hooks in the generic kernel reclaim algorithm.  Getting
> something like that in mainline will be at best tricky.

Yes, it does mean doing something in the reclamation path.

> 
> 
> -rohit
> 
-- 

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    Chandra Seetharaman               | Be careful what you choose....
              - sekharan at us.ibm.com   |      .......you may get it.
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