Re: JFFS3 & performance

Artem B. Bityuckiy
2004-12-18T12:23:26Z

On Fri, 17 Dec 2004, [iso-8859-1] Jörn Engel wrote:

> On Fri, 17 December 2004 10:56:22 +0000, Artem B. Bityuckiy wrote:
> >
> > > Another idea, calculate the CRC backwards(from the end of the buffer to the beginning).
> > > That give better L1 cache behaviour.
> > >
> > Why (may be some URL)? For all archs?
>
> Sounds rather odd indeed. Most CPUs I know about either have no
> hardware-prefetch, can only prefetch forward or can prefetch both
> forward and backward. In either case, calculating the CRC backward
> should either be the same speed or slower than going forward.
>
> But I like to learn something new.
Hmm, I'm curious and exploring that too. Take a glimps at
http://gcc.gnu.org/projects/prefetch.html
There are some useful references there.

>
> Jörn
>
> --
> I've never met a human being who would want to read 17,000 pages of
> documentation, and if there was, I'd kill him to get him out of the
> gene pool.
> -- Joseph Costello
>

--
Best Regards,
Artem B. Bityuckiy,
St.-Petersburg, Russia.