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Date: Mon, 19 Mar 2012 15:20:46 +0100
From: Andrea Arcangeli <aarcange@redhat.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Avi Kivity <avi@redhat.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
        Paul Turner <pjt@google.com>,
        Suresh Siddha <suresh.b.siddha@intel.com>,
        Mike Galbraith <efault@gmx.de>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Lai Jiangshan <laijs@cn.fujitsu.com>, Dan Smith <danms@us.ibm.com>,
        Bharata B Rao <bharata.rao@gmail.com>,
        Lee Schermerhorn <Lee.Schermerhorn@hp.com>,
        Rik van Riel <riel@redhat.com>, Johannes Weiner <hannes@cmpxchg.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC][PATCH 00/26] sched/numa
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On Mon, Mar 19, 2012 at 02:39:31PM +0100, Peter Zijlstra wrote:
> On Mon, 2012-03-19 at 14:04 +0100, Andrea Arcangeli wrote:
> > In implementation terms the scheduler is simplified and it won't work
> > as well as it should with massive CPU overcommit. But I had to take
> > shortcuts to keep the complexity down to O(N) where N is the number of
> > CPUS 
> 
> Yeah I saw that, you essentially put a nr_cpus loop inside schedule(),
> obviously that's not going to ever happen.

lol Would be fun if such a simplification would still perform better
than your code :).

Yeah I'll try to fix that but it's massively complex and frankly
benchmarking wise it won't help much fixing that... so it's beyond the
end of my todo list.