Once upon a time, Zbigniew Jędrzejewski-Szmek zbyszek@in.waw.pl said:
On Tue, Apr 04, 2023 at 11:17:50AM +0200, Jakub Jelinek wrote:
Why a subrpm? Should be possible to just arrange for one src.rpm to build the library twice and install the x86-64-v3 into /usr/lib64/glibc-hwcaps/x86-64-v3/ Perhaps come with some macro to simplify that for packagers.
If we start compiling libaries twice, it'd double the package sizes (or actually more than double, since in the benchmarks the code size with -v3 is also increased slightly). I assume people would want to get the optimized form split out to a subpackage so people who don't use this, don't pay the price. If we use the new "dynamic subpackages" feature of RPM, and some smart macros, this could even not be a big packaging burden.
Yeah, it'd be back to the i386/i586/i686 days... which was a bit of a PITA sometimes. But cramming multiple architectures of core libraries into a single RPM would be bad for disk space, image size, downloads, etc.
But something that didn't exist in the i386/i686 days is containers - whether base images like for podman or full things like Flatpaks. Before going too deep into multi-level architectures, that should be taken into account.