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Date: Fri, 9 Sep 2011 18:56:37 +0530
From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>,
        Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
        Vladimir Davydov <vdavydov@parallels.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Bharata B Rao <bharata@linux.vnet.ibm.com>,
        Dhaval Giani <dhaval.giani@gmail.com>,
        Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
        Ingo Molnar <mingo@elte.hu>, Pavel Emelianov <xemul@parallels.com>
Subject: Re: CFS Bandwidth Control - Test results of cgroups tasks pinned vs
 unpinnede
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* Peter Zijlstra <a.p.zijlstra@chello.nl> [2011-09-09 14:31:02]:

> > We have setup cgroups and their hard limits so that in theory they should
> > consume the entire capacity available on machine, leading to 0% idle time.
> > That's not what we see. A more detailed description of the setup and the problem
> > is here:
> > 
> > https://lkml.org/lkml/2011/6/7/352
> 
> That's frigging irrelevant isn't it? A patch should contain its own
> justification.

Agreed my bad. I was (wrongly) setting the problem context by posting
this in response to Paul's email where the problem was discussed.

> > One
> > possibility is to make the idle load balancer become aggressive in
> > pulling tasks across sched-domain boundaries i.e when a CPU becomes idle
> > (after a task got throttled) and invokes the idle load balancer, it
> > should try "harder" at pulling a task from far-off cpus (across
> > package/node boundaries)?
> 
> How about we just live with it?

I think we will, unless the load balancer can be improved (which seems unlikely 
to me :-()

- vatsa