Re: [PATCH] Adaptive read-ahead v4

[Andrew Morton <akpm@osdl.org>]

WU Fengguang <wfg@mail.ustc.edu.cn> wrote:
>
> ...
> > > +	unsigned long pgra_backward;
> > > +	unsigned long pgra_backward_hit;
> > > +	unsigned long pgra_backward_eof;
> > > +
> > > +	unsigned long ra_random;	/* read-ahead on seek-and-read-pages */
> > > +	unsigned long ra_random_return;
> > > +	unsigned long ra_random_eof;
> > > +	unsigned long pgra_random;
> > > +	unsigned long pgra_random_hit;
> > > +	unsigned long pgra_random_eof;
> > > +
> > >  };
> > 
> > Without actually understanding what you're doing, wouldn't a struct
> > for all those groups make sense?  I bet it can simplify the actual
> > code as well.
> Yeah, I did not expect the structure to grow so large.

All that stuff shouldn't remain there long-term.

> It should be better to create a stand alone struct and create a
> dedicated entry in /proc/. The data would be a nice hint for
> administrators who care the performance.

You should treat such informaton as a development aid, really.  People are
very unlikely to look at it in real life.