Re: Announcing Fedora Core 6 Test 1 (5.90)

[Arjan van de Ven <arjan fenrus demon nl>]

On Sun, 2006-07-09 at 04:50 -0400, Dave Jones wrote:
> On Sun, Jul 09, 2006 at 10:43:32AM +0200, Arjan van de Ven wrote:
>  > On Sat, 2006-07-08 at 16:38 -0400, Dave Jones wrote:
>  > > On Sat, Jul 08, 2006 at 10:27:55PM +0200, Andreas Thienemann wrote:
>  > > 
>  > >  > Several legacy i586 systems are used as routers and I'd hate to leave them 
>  > >  > on FC5.
>  > > 
>  > > The buildsys was tweaked a few days ago, and 586 kernels have been popping out
>  > > since then.  test2 should be fine.
>  > 
>  > now to go a step further; cmov isn't actually a performance gain on any
>  > cpu sold in the last year or two. Why ship the i686 kernel at all over
>  > an i586 kernel? Why not ship ONLY a i586 kernel?
> 
> This has crossed my mind, and I did some investigation on this a month or two ago.
> You'd still want gcc to schedule instructions optimally for newer cpus
> (-mtune-generic seems to handle this),

yes absolutely; no doubt about that

>  but iirc adding -march=i586 somehow
> affects the behaviour of -mtune in a negative way.

hmmm that's a good question for the gcc guys... I'm actually surprised
by this. Maybe -mtune=i686 ?