RE: [RFC PATCH 0/4]: affinity-on-next-touch

[Stefan Lankes <lankes@lfbs.rwth-aachen.de>]

> -----Original Message-----
> From: Andi Kleen [mailto:andi@firstfloor.org]
> Sent: Monday, May 11, 2009 6:37 PM
> To: Stefan Lankes
> Cc: 'Andi Kleen'; linux-kernel@vger.kernel.org;
> Lee.Schermerhorn@hp.com; linux-numa@vger.kernel.org;
> brice.goglin@inria.fr; 'Terboven, Christian'; anmey@rz.rwth-aachen.de;
> 'Boris Bierbaum'
> Subject: Re: [RFC PATCH 0/4]: affinity-on-next-touch
> 
> > By default, mbind only has an effect on new allocations. I think that
> this
> 
> Nope, it affects existing pages too, it can even move pages
> if you ask for it.
> 

I know this possibility. I thought that "affinity-on-next-touch" fit better
to madvise. Brice told already the technical reasons for preferring of
madvise.

> > For instance, Norden's PDE solvers using adaptive mesh refinements
> (AMR) [1]
> > is an application with a dynamic access pattern. We use this example
> to
> > evaluate the performance of our patch. We ran this solver on our
> > quad-socket, dual-core Opteron 875 (2.2GHz) system running CentOS
> 5.2. The
> > code was already optimized for NUMA architectures. Before the arrays
> are
> > initialized, the threads are bound to one core. In our test case, the
> solver
> > needs 5318s. If we use our kernel extension, the solver needs 4489s.
> 
> Okay that sounds like good numbers.
> 
> > Currently, we are testing some other apps.
> 
> Please keep the list updated.
> 

I will do it.

Stefan