> Hi!
>
> > > > This works and gets rid of the two jmps that everybody complained
> > > > about.
> > >
> > > Are you sure? I saw reports where it depended on place in _page_
> > > (imagine udelay loop at page boundary). So you maybe should .align
> > > PAGE_SIZE.
> >
> > I presume this is a joke.
>
> Sorry, it is not. Someone shown timings of empty loop at they were
> dependend on placement of code in page. (It gives plenty of sense if
> code happens to cross page boundary.)
>
It does not make any sense. That kind is situation is the primary
reason for the instruction-queue (which includes the 32-byte code-
queue + the prefetcher + the external cache). When register-to-
register looping operations occur, everything will have already been
fetched. It is only when memory oprands occur, or you run off the
cache-line with new code, that any new code fetches occur.
Cheers,
Dick Johnson
***** FILE SYSTEM WAS MODIFIED *****
Penguin : Linux version 2.1.123 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/