Re: Raising the minimum required s390x CPU to z196?

Aurelien Jarno <[email protected]> Tue, 6 Feb 2018 21:01:39 +0100

Newsgroups	gmane.linux.debian.ports.s390
Message-ID	<[email protected]>

On 2018-01-31 15:38, Aurelien Jarno wrote:
> Hi all,
> 
> The Debian s390x port currently officially defaults to the z900 ISA.
> That's what our GCC defaults too, but I wouldn't be surprised if a few
> packages use a slightly newer ISA.
> 
> Unfortunately more and more packages require a newer ISA, usually at
> least z196. This is the case of at least nodejs, go and rustc. It should
> be noted that it's not a question of passing the right flag to GCC, but
> rather these packages have their own JIT compiler which has been written
> for a z196 ISA minimum.
> 
> For go we currently use gccgo instead of golang, which is not really
> an optimal solution and prevents many packages to build. For the same
> reason rustc is not available on s390x, which might become problematic
> soon (for example rsvg will require it soon). Finally recent versions
> of nodejs require at least a z196 CPU, so we have to drop all nodejs
> packages if we want to keep the baseline as z900.
> 
> In my opinion we don't really have any other choice than raising the
> minimum ISA to z196, even if this CPU is less than 7 years old. The
> the only other alternative I can think about would be to have people
> committing to maintain patches lowering the minimum ISA for the above
> packages. I started to work on that for go a few months ago, but
> unfortunately that's a huge work as upstream keeps moving.

Note that both hercules and QEMU are able to simulate a z196 CPU, or at
least the facilities used by the Linux kernel and user land when built
for z196.

Aurelien

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
[email protected]                 http://www.aurel32.net

signature.asc (application/pgp-signature, 833 B)