Re: mmap() is slower than read() on SCSI/IDE on 2.0 and 2.1
Pauline Middelink (middelin@polyware.nl)
Thu, 17 Dec 1998 13:39:54 +0100
On Thu, Dec 17, 1998 at 06:52:50AM +0000, Linus Torvalds wrote:
> In article <Pine.LNX.4.03.9812170121030.5325-100000@mirkwood.dummy.home>,
> Rik van Riel <H.H.vanRiel@phys.uu.nl> wrote:
> >
> >It should be a pretty safe bet to assume that we are
> >going in the direction of the lowest page counts --
> >what's already mapped (and has a higher count) is
> >where we came from.
>
> Umm, the easiest hint is probably to just look at the faulting address.
> We have it available, after all.
>
> Basically, if the faulting address is at offset 0 of the page, we're
> probably walking upwards. If it's in the middle, we probably have
> random access. And if it is at the end, the user is probably walking
> downwards.
But this only works for byte granularity, not for something larger.
Met vriendelijke groet,
Pauline Middelink
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