Re: Architecture baseline for Forky
On Sun, Oct 26, 2025 at 01:21:29PM +0100, Bastian Blank wrote:
> Hi
Hi Bastian,
> We never did a real discussion about architecture baselines before, but I think
> we should do that. We also don't have any guidelines what we as Debian want to
> actually support. But given that we are a general purpose distribution, we
> have to find a balance.
you did not provide data to show what your "balance" is about,
and discussions not based on data are rarely productive.
Your proposal would make many users unhappy, it would be you who has to
show the benefits.
Whether your proposal to drop support for v1 amd64 hardware is even
worth discussing depends a lot on whether the typical performance
improvement is 2% or 20%.
It would also be useful to have data for security hardening in this
discussion.
We are shipping an additional version of the Python interpreter built
without PIE because this one hardening feature alone had a large enough
negtive impact on performance that it was not suitable for some users.
Typical for a discussion not based on data would be if it later turns
out that there was a huge discussion with GR and everything about
something that only makes 2% difference, but building HPC software
with hardening flags costs 20%.
> As a general guidance I would like to aim for a ten to 15 years support range
> at release time. The cutoff in respect to the expected 2027 release date of
> Forky would therefor be 2012 to 2017. More time is given for widely used
> architectures, less for more specialized ones.
>...
> ## amd64 (and i386)
>
> * x86-64-v2: Supported since around 2008[^x86]. Used in RedHat 9[^redhat9x86].
> * x86-64-v3: Supported since around 2013-2015[^x86]. Used in RedHat
> 10[^redhat10].
What RHEL uses is not particularly relevant, since enterprise
distributions do not target the cheap low-end systems that are
manufactured and used for a long time.
> I propose to use the x86-64-v2 baseline in Forky.
> It gives us more then the 15 years
>...
You are talking about the mostly irrelevant "supported by one CPU" date.
It is also telling that you aren't mentioning v4, which was supported by
Intel desktop CPUs in the past - but current Intel desktop and laptop CPUs
are not supporting it.
Based on your proposal, you want us to drop support for Intel desktops
and laptops sold today in 4-9 years.
Actually relevant would be the date when the last CPU was sold that did
not support the new baseline.
15 years after the last CPU was sold would be a point where usage
becomes quite low.
Even the introduction of the most recent new v1 CPU was not more than
10 years ago, we are still at least a decade away from the point where
v1 usage could be called retro computing.
cu
Adrian
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