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 |
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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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