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

[Lee Schermerhorn <Lee.Schermerhorn@hp.com>]

On Fri, 2009-06-12 at 12:32 +0200, Andi Kleen wrote:
> On Thu, Jun 11, 2009 at 08:45:29PM +0200, Stefan Lankes wrote:
> > > Your patches seem to have a lot of overlap with
> > > Lee Schermerhorn's old migrate memory on cpu migration patches.
> > > I don't know the status of those.
> > 
> > I analyze Lee Schermerhorn's migrate memory on cpu migration patches
> > (http://free.linux.hp.com/~lts/Patches/PageMigration/). I think that Lee
> > Schermerhorn add similar functionalities to the kernel. He called the
> > "affinity-on-next-touch" functionality "migrate_on_fault" and uses in his
> > patches the normal NUMA memory policies. Therefore, his solution fits better
> > to the Linux kernel. I tested his patches with our test applications and got
> > nearly the same performance results. 
> 
> That's great to know.
> 
> I didn't think he had a per process setting though, did he?

Hi, Andi.

My patches don't have per process enablement.  Rather, I chose to use
per cpuset enablement.  I view cpusets as sort of "numa control groups"
and thought this was an appropriate level at which to control this sort
of behavior--analogous to memory_spread_{page|slab}.  That probably
needs to be discussed more widely, tho'.

> 
> > I found only patches for the kernel 2.6.25-rc2-mm1. Does someone develop
> > these patches further?
> 
> Not to much knowledge. Maybe Lee will pick them up again now that there
> are more use cases.
> 
> If he doesn't have time maybe you could update them?

As I mentioned earlier, I need to sort out the interaction with the
memory controller.  It was changing too fast for me to keep up in the
time I could devote to it.

Lee