Re: [PATCH v2] ld.so.8: Update "Hardware capabilities" section for glibc 2.31.

[Florian Weimer <fweimer@redhat.com>]

* Carlos O'Donell:

> +Care should be taken when packaging such application with a package manager,
> +particularly the scenario where an optimized library is being removed.  With
> +certain package managers, particularly rpm, the newer version of the

Twice “particularly”.

> +application is installed first, which means that for a period of time during
> +the upgrade all applications that use the library may start with a mixed set of
> +libraries e.g.  the old library from the feature-based search path, and new

Commas arount e.g.?

> +libraries from the upgrade. To avoid this scenario the new library version
> +should delete all known optimized libraries in the post-install phase.

There is a different mechanism: Debian has patched glibc to disable
hwcap subdirectors if the file /etc/ld.so.nohwcap exists.

You now list the AT_PLATFORM directories (determined by the kernel on
most architectures) along the regular hwcaps directories, although they
are handled somewhat differently.  For example, on s390x, if you have a
“z15” machine (as indicated by AT_PLATFORM), the “z13” subdirectory is
not selected.  ldconfig will add it to the cache, but it will not be
used at run time.  I'm not sure if your proposed description gives
readers the right idea what happens.

Thanks,
Florian