[CentOS-devel] glibc-2.28-145.el8 with glibc-hwcaps support is coming to CentOS Stream 8

On 08/01/2021 10:15, Florian Weimer wrote:
> * Fabian Arrotin:
> 
>> Thanks a lot for the announce, really appreciated to be aware of what's
>> coming .
>> I'd (myself) like to see some kind of announces being sent on the public
>> list so that everybody can follow what's being worked on and so what to
>> expect in Stream packages (as of course there is no official public
>> Release Notes -yet- , appearing for RHEL, so downstream)
> 
> I'm going to let others comment on that.
> 
>> Now back to the x86 cpu infra : does that mean that to *build* Stream
>> packages (like gblic) we need at least a minimum instructions set in the
>> CPU (builder side that is) ?
> 
> glibc itself continues to use IFUNCs on x86-64 to select optimized
> function implementations, based on CPU capabilities.  This means that
> baseline x86-64 support remains sufficient for building the glibc
> package.
> 
> I can image that in the future, there will be some packages which build
> shared objects for x86-64-v3 (in addition to baseline x86-64, with
> run-time selection later), and which test all implementations at build
> time.  In such a scenario, the builders would have to support x86-64-v3.
> 
> In related news, we plan to build CentOS Stream 9 with a x86-64-v2
> baseline:
> 
>   Building Red Hat Enterprise Linux 9 for the x86-64-v2 microarchitecture level
>   <https://developers.redhat.com/blog/2021/01/05/building-red-hat-enterprise-linux-9-for-the-x86-64-v2-microarchitecture-level/>
> 

Thanks a lot, that's exactly the kind of information I wish we had when
we started to build the new infra for Stream 9 .... now to see if what
deployed as hardware for this is enough :)


-- 
Fabian Arrotin
The CentOS Project | https://www.centos.org
gpg key: 17F3B7A1 | twitter: @arrfab