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Date: Tue, 16 Jun 2009 17:59:07 +0200
From: Nick Piggin <npiggin@suse.de>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Hugh Dickins <hugh.dickins@tiscali.co.uk>,
       Pekka Enberg <penberg@cs.helsinki.fi>,
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       akpm@linux-foundation.org, kamezawa.hiroyu@jp.fujitsu.com,
       lizf@cn.fujitsu.com, mingo@elte.hu, yinghai@kernel.org
Subject: Re: [GIT PULL v2] Early SLAB fixes for 2.6.31
Message-ID: <20090616155907.GA1552@wotan.suse.de>
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On Tue, Jun 16, 2009 at 11:12:58AM -0400, Christoph Lameter wrote:
> On Tue, 16 Jun 2009, Nick Piggin wrote:
> 
> > There aren't too many significant code simplifications AFAIKS.
> 
> The code simplification comes from the ability to run the same code during
> boot that is also running when the full system is operational. I thought
> the intend of this whole exercise was to avoid special casing as much as
> possible and reduce the amount of code specifically duplicated for boot
> situations?

That is one of the advantages, yes. As far as I can see though,
there isn't like *huge* amounts of things you can simplify. And
if it is just a matter of removing a few branches from a few
cold paths, then it isn't necessarily a good reason to push
branches into the slab and page allocators.

I'm not saying we definitely should go one way or the other, I
would just like to wait and see.