Re: [ck] Re: [PATCH] vm - swap_prefetch-15

[Gustavo Barbieri]

On 10/7/05, Pekka Enberg <penberg@xxxxxxxxxxxxxx> wrote:
> Hi,
>
> On 10/7/05, Con Kolivas <kernel@xxxxxxxxxxx> wrote:
> > Good point, thanks! Any and all feedback is appreciated.
>
> Well, since you asked :-)
>
> > +/*
> > + * How many pages to prefetch at a time. We prefetch SWAP_CLUSTER_MAX *
> > + * swap_prefetch per PREFETCH_INTERVAL, but prefetch ten times as much at a
> > + * time in laptop_mode to minimise the time we keep the disk spinning.
> > + */
> > +#define PREFETCH_PAGES()     (SWAP_CLUSTER_MAX * swap_prefetch * \
> > +                                     (1 + 9 * laptop_mode))
>
> This looks strange. Please either drop the parenthesis from PREFETCH_PAGES or
> make it a real static inline function.

Or make it a "const static" variable, so compiler will check types and
everything, but the symbol will not be present in the binary, causing
no overhead. So it could be:

const unsigned PREFETCH_PAGES = (SWAP_CLUSTER_MAX * swap_prefetch * \
        (1 + 9 * laptop_mode));

--
Gustavo Sverzut Barbieri
---------------------------------------
Computer Engineer 2001 - UNICAMP
GPSL - Grupo Pro Software Livre
Cell..: +55 (19) 9165 8010
Jabber: gsbarbieri@xxxxxxxxxx
  ICQ#: 17249123
   MSN: barbieri@xxxxxxxxx
 Skype: gsbarbieri
   GPG: 0xB640E1A2 @ wwwkeys.pgp.net
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/