Messages in this thread |  | | | Date | Wed, 16 Jan 2008 17:07:20 +0800 | | From | Fengguang Wu <> | | Subject | Re: [patch] Converting writeback linked lists to a tree based data structure | |
On Tue, Jan 15, 2008 at 09:51:49PM -0800, Andrew Morton wrote:
> 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?
Ordering by dirtied_when or i_ino, either is OK.
> What is "blockade waiting"?
Some inodes/pages cannot be synced now for some reason and should be
retried after a while.
> > Then to do better ordering by adopting radix tree(or rbtree
> > if radix tree is not enough),
>
> ordering of what?
Switch from time to location.
> > 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.
That would be easy. s_more_io and s_more_io_wait can all be converted
to radix trees.
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