On 08/31/2017 04:29 AM, Florian Weimer wrote:
I would like to tweak glibc so that it only builds one POWER 620/970
libc for ppc64, and not multiple libcs with POWER6/POWER7/POWER8
optimizations.
This does not affect ppc64le in any way.
The reason for this change is that the ppc64 builders are awfully slow
as of late, and the multiple builds (four times currently) currently
make ppc64 the slowest architecture to build by quite a margin.
Any comments?
IBM has argued in the past that these POWER6/POWER7/POWER8 variants were
important and brought performance gains that were not attainable with
IFUNCs alone.
Therefore we implemented this using IBM's guidance in Fedora to provide
the best possible performance for our users systems.
This problem doesn't go away for ppc64le either, once we have POWER9
systems, it will be a question of doing POWER9 multilibs also?
In summary:
- Is the added performance of the multilib builds for users worth the
build cost and development slowdown caused by slow builds?
--
Cheers,
Carlos.