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Date: Fri, 26 Oct 2007 19:41:44 -0700
From: Paul Jackson <pj@sgi.com>
To: Christoph Lameter <clameter@sgi.com>
Cc: rientjes@google.com, Lee.Schermerhorn@hp.com, akpm@linux-foundation.org,
       ak@suse.de, linux-kernel@vger.kernel.org
Subject: Re: [patch 2/2] cpusets: add interleave_over_allowed option
Message-Id: <20071026194144.6042316a.pj@sgi.com>
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Christoph wrote:
> Yes. We should default to Choice B. Add an option MPOL_MF_RELATIVE to 
> enable that functionality? A new version of numactl can then enable
> that by default for newer applications.

I'm confused.  If B is the default, then we don't need a flag to
enable it, rather we need a flag to go back to the old choice A.

So are you saying that:
 1) Choice A remains the default for the kernel unless
    MPOL_MF_RELATIVE is added, or
 2) that the new default for the kernel is Choice B,
    unless MPOL_MF_RELATIVE is specified, asking to
    revert to the original Choice A behaviour?

Perhaps, either way, whatever compatibility flag we have should be
something that can be forced on an application from the outside,
perhaps as a per-system mode flag in /sys, or a per-cpuset mode flag,
or a per-task operation, by what mechanism is not clear.

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401