From: Con Kolivas <kernel@kolivas.org>
To: Paul Jackson <pj@sgi.com>
Subject: Re: [PATCH] mm: implement swap prefetching
Date: Wed, 8 Feb 2006 16:33:11 +1100
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On Wed, 8 Feb 2006 04:06 pm, Con Kolivas wrote:
> On Wed, 8 Feb 2006 03:46 pm, Paul Jackson wrote:
> > Con, responding to Nick:
> > > > It introduces global cacheline bouncing in pagecache allocation and
> > > > removal and page reclaim paths, also low watermark failure is quite
> > > > common in normal operation, so that is another global cacheline write
> > > > in page allocation path.
> > >
> > > None of these issues is going to remotely the target audience. If the
> > > issue is how scalable such a change can be then I cannot advocate
> > > making the code smart and complex enough to be numa and cpuset aware..
> > > but then that's never going to be the target audience. It affects a
> > > particular class of user which happens to be quite a large population
> > > not affected by complex memory hardware.
> >
> > How about only moving memory back to the Memory Node (zone) that it
> > came from?  And providing some call that Christoph Lameters migration
> > code can call, to disable or fix this up, so you don't end up bringing
> > back pages on their pre-migration nodes?
>
> Sounds good, and this is what I was hoping to be able to do; first I need
> to see the best time and place to get this information (and learn some more
> about the code).

Actually it's looking an awful lot like I should just use one thread per pgdat 
and have per node data. Given that, I should probably just make this a task 
for kswapd since that is what they already are - and the name isn't wrong 
either.

Cheers,
Con
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