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From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Paul Jackson <pj@sgi.com>
Subject: Re: [PATCH] cpuset and sched domains: sched_load_balance flag
Date: Wed, 3 Oct 2007 02:14:48 +1000
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On Wednesday 03 October 2007 17:25, Paul Jackson wrote:
> Nick wrote:
> > BTW. as far as the sched.c changes in your patch go, I much prefer
> > the partition_sched_domains API: http://lkml.org/lkml/2006/10/19/85
> >
> > The caller should manage everything itself, rather than
> > partition_sched_domains doing half of the memory allocation.
>
> Please take a closer look at my partition_sched_domains() and its
> interface to the scheduler.
>
> You should recognize this API, once you look at it.  It simply passes
> the full flat, hard partition, in its entirety.  This is the
> partitioning that you speak of, I believe.  It's here; just not where
> you expected it.
>
> The portion of the code that is in kernel/sched.c is just a little bit
> of optimization.  It avoids rebuilding all the sched domains and
> reattaching every task to its sched domain; rather it determines which
> sched domains were added or removed and just rebuilds them.
>
> Once you take a closer look, I hope you will agree that this new
> interface between the cpuset and sched code provides a cleaner
> separation.

I don't know what you think I said that is incorrect and requires me to
look at again. I don't like your partition_sched_domains API because
of the allocation thing. So I prefer the existing (or better, the simplified
version in my patch referenced).

The caller should determine which domain to rebuild and reattach.
Simple.