Re: [PATCH 8/15] sched: Add parameter sched_mn_power_savings to control MN domain sched policy

[Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>]

* Peter Zijlstra <peterz@infradead.org> [2009-08-24 16:56:18]:

> On Thu, 2009-08-20 at 15:39 +0200, Andreas Herrmann wrote:
> > Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
> > ---
> 
> > +#ifdef CONFIG_SCHED_MN
> > +	if (!err && mc_capable())
> > +		err = sysfs_create_file(&cls->kset.kobj,
> > +					&attr_sched_mn_power_savings.attr);
> > +#endif
> 
> *sigh* another crappy sysfs file
> 
> Guys, can't we come up with anything better than sched_*_power_saving=n?
> 
> This configuration space is _way_ too large, and now it gets even
> crazier.

Hi Peter and Andreas,

Actually we had sched_power_savings and related simplifications, but
that did not really simplify the interface.

As for this mulit-node MN stuff, Gautham had posted a better solution
to propagate the sched_mc flags without need for new sysfs file and
related changes.

Please take a look at: http://lkml.org/lkml/2009/3/31/137 and
http://lkml.org/lkml/2009/3/31/142 which actually degenerates the
domain.

However Andreas's requirement seem to indicate multiple nodes within
a single socket.  I did not yet completely understand that topology.
Some for of smart degeneration may save an additional tunable here.

Thanks for pointing me to this patch.

--Vaidy