Re: [PATCH 5/9] readahead: on-demand readahead logic

[Fengguang Wu <wfg@mail.ustc.edu.cn>]

On Wed, Jun 13, 2007 at 03:51:14PM +1000, Rusty Russell wrote:
> > >  static unsigned long
> > >  ondemand_readahead(struct address_space *mapping,
> > >  		   struct file_ra_state *ra, struct file *filp,
> > > -		   struct page *page, pgoff_t offset,
> > > +		   bool hit_lookahead_marker, pgoff_t offset,
> > 
> > Or use names like async/is_async for hit_lookahead_marker?
> 
> I wasn't sure.  The argument says "we've hit a marker, so do readahead
> even if doesn't look sequential.".  Now, you and I know that only
> happens if it's an async readahead, but that's not really relevant to
> this function.

Yeah, it's an interface for the message "hey I hit a readahead marker".
That's the point!

> OK, here is revised patch with your changes:
> 
> ====
> Split ondemand readahead interface into two functions.  I think this
> makes it a little clearer for non-readahead experts (like Rusty).
> 
> Internally they both call ondemand_readahead(), but the page argument
> is changed to an obvious boolean flag.
> 
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Acked-by: Fengguang Wu <wfg@mail.ustc.edu.cn>

Thank you,
Fengguang