[PATCH] zlib: Optimize inffast when copying direct from output

[Joakim Tjernlund]

Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote on 24/11/2009 04:12:43:
>
> On Tue, 2009-11-10 at 10:00 +0100, Joakim Tjernlund wrote:
> > JFFS2 uses lesser compression ratio and inflate always
> > ends up in "copy direct from output" case.
> > This patch tries to optimize the direct copy procedure.
> > Uses get_unaligned() but only in one place.
> > The copy loop just above this one can also use this
> > optimization, but I havn't done so as I have not tested if it
> > is a win there too.
> > On my MPC8321 this is about 17% faster on my JFFS2 root FS
> > than the original.
> > ---
> >
> >  Would like some testing of the PowerPC boot wrapper and
> >  a LE target before sending it upstream.
>
> Well, you should probably submit that patch to lkml then :-)

I have(with LE fixes), Andrew Morton has it.

>
> I'm not sure its going to work to use get_unaligned() like that on all
> archs .. it might be definitely something to discuss on some more
> appropriate mailing list.

Oh, why not? Is that because I am using it wrongly or because xx_unaligned
is impl. incorrectly on some archs?

      Jocke