Re: [patch] Converting writeback linked lists to a tree based datastructure

From: Andrew Morton
Date: Wed Jan 16 2008 - 00:52:19 EST


On Wed, 16 Jan 2008 12:55:07 +0800 Fengguang Wu <wfg@xxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxx> 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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/