Re: [patch 12/17] vfs: pagecache usage optimization for pagesize!=blocksize

[Nick Piggin <nickpiggin@yahoo.com.au>]

On Tuesday 29 July 2008 09:09, Andrew Morton wrote:
> On Mon, 28 Jul 2008 19:00:32 -0400
>
> Christoph Hellwig <hch@infradead.org> wrote:
> > On Mon, Jul 28, 2008 at 03:46:36PM -0700, akpm@linux-foundation.org wrote:
> > > From: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
> > >
> > > When we read some part of a file through pagecache, if there is a
> > > pagecache of corresponding index but this page is not uptodate, read IO
> > > is issued and this page will be uptodate.
> >
> > I was under the impression we wanted to do this in a nicer way than
> > the hacky method?
>
> The only description I've seen of "a nicer way" is vague two-word
> descriptions of "changing readpage".  Or something.  No indication of
> what those changes are, nor who will implement them nor when.
>
> That just isn't solid enough to block a change which has significant
> performance benefits.

Yes I thought it would be nicer to do it by changing readpage, but I
said I'm happy to try to consolidate them myself down the track. It
is fairly low impact on core code.