Date: Tue, 15 Jan 2008 21:51:49 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Michael Rubin <mrubin@google.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
       linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [patch] Converting writeback linked lists to a tree based data
 structure
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On Wed, 16 Jan 2008 12:55:07 +0800 Fengguang Wu <wfg@mail.ustc.edu.cn> wrote:

> On Tue, Jan 15, 2008 at 08:42:36PM -0800, Andrew Morton wrote:
> > On Wed, 16 Jan 2008 12:25:53 +0800 Fengguang Wu <wfg@mail.ustc.edu.cn> wrote:
> > 
> > > list_heads are OK if we use them for one and only function.
> > 
> > Not really.  They're inappropriate when you wish to remember your
> > position in the list while you dropped the lock (as we must do in
> > writeback).
> > 
> > A data structure which permits us to interate across the search key rather
> > than across the actual storage locations is more appropriate.
> 
> I totally agree with you. What I mean is to first do the split of
> functions - into three: ordering, starvation prevention, and blockade
> waiting.

Does "ordering" here refer to ordering bt time-of-first-dirty?

What is "blockade waiting"?

> Then to do better ordering by adopting radix tree(or rbtree
> if radix tree is not enough),

ordering of what?

> and lastly get rid of the list_heads to
> avoid locking. Does it sound like a good path?

I'd have thaought that replacing list_heads with another data structure
would be a simgle commit.
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