[Debian-ppc64-devel] Status of debian ppc64?

[Sven Luther]

On Tue, Mar 08, 2005 at 01:45:41PM +0100, Andreas Jochens wrote:
> On 05-Mar-08 13:08, Sven Luther wrote:
> > No, i believe you are wrong, or partially so at least. I mean, it may have
> > changed in the last few month, but last this was discussed, both redhat and
> > suse where taking the biarch approach, while gentoo goes the pure-64bit
> > approach.
> 
> What exactly do you mean by 'biarch approach' vs. 'pure-64bit approach'?
> I guess that the term 'pure-64bit approach' comes from the amd64 case.
> The Debian amd64 'pure64' port started with a setup and toolchain which 
> was not able to produce 32 binaries. But this is history. 
> Since a long time the Debian amd64 port has a 'biarch' toolchain 
> which can produce 32 bit binaries and 32 bit binaries and libraries 
> run without problems on the amd64 'pure64' port. 
> 
> The ppc64 port on alioth also uses a biarch setup and toolchain. 
> 32-bit binaries and libraries will run fine.

I think the difference is in what you run per default, 32bit vs 64bit, and if
you have powerpc or ppc64 as arch in the packages.

Notice that the ppc64 port on alioth is not an official port too.

> > > The Debian ppc64 port on alioth is quite similar to the ppc64 ports of
> > > the other major distributions. One minor difference between RedHat/Suse 
> > > on one side and Debian/Gentoo on the other is that RedHat and Suse 
> > > put native 64-bit libraries in '/lib64' and 32-bit libraries in '/lib', 
> > > while Debian and Gentoo put native 64-bit libraries in '/lib' and
> > > 32-bit libraries in '/lib32'.
> > 
> > Exactly what i was saying, the only difference is the extent of the 64bit
> > rebuilds. 
> > 
> > But then, again the IBM ppc64 folk tell me that there is a slight performance
> > hit in running 64bit userland if it is not necessary, and i wonder what you
> > reply to this ? 
> 
> It is too early to confirm or reject this. I only made some very 
> non-scientific tests with the standard tools and with compilations.
> In these prelimiary test, I could not detect any significant differences.
> Do you have any detailed numbers or specific tests that I could run to
> verify this?

Nope, but since it comes from the guys who work at IBM ozlabs doing ppc64
port, i am ported to believe them.

Friendly,

Sven Luther