On Wed, 20 Jan 2016 13:46:53 -0500
"Carlos O'Donell" <carlos(a)redhat.com> wrote:
On 01/20/2016 06:16 AM, Dan Horák wrote:
> The current distro defaults are (/usr/lib/rpm/redhat/rpmrc)
> optflags: ppc64 %{__global_cflags} -m64
> optflags: ppc64p7 %{__global_cflags} -m64 -O3 -mcpu=power7
> -mtune=power7 optflags: ppc64le %{__global_cflags} -m64
> -mcpu=power7 -mtune=power8
The ppc64le case needs to become '-mcpu=power8 -mtune=power8', as
Steven Munroe notes the only official ppc64le support is with POWER8
hardware.
> And gcc has its own defaults which can be set during the build.
>
> The Fedora infrastructure is currently using Power8 HW for the main
> Koji build system [1] to produce the binary rpms for the
> distrobution and we have planned to reuse the previous Power7+
> builders for COPR [2] and Fedora Cloud.
This will mean that COPR cannot build POWER8 enabled binaries, and
that would be a shame for users of newer hardware.
> Carlos, Florian, could you please comment on the situation?
At present glibc in fedora rawhide requires POWER8 hardware.
Why? We build optimized variants of the runtime for POWER8 hardware
and need POWER8 hardware to test the resulting binaries (native
build).
This means that glibc for fedora rawhide will be unbuildable in COPR
until COPR is upgraded to POWER8 machines.
However, we can change that, as Florian suggets, it's up to the Fedora
Power community to make a decision as to what is needed to best serve
the IBM hardware users.
We currently have the following support in place (from glibc.spec in
rawhide):
# 64-bit BE:
# - Power 620 / 970 ISA (default runtime, compatile with POWER4 and
# newer)
# - Provided for the large number of PowerPC G5 users.
# - IFUNC support provides optimized core routines for POWER6,
# POWER7, and POWER8 transparently (if not using specific
# runtimes below)
# - POWER6 (has power6x symlink to power6, enabled via AT_PLATFORM)
# - Legacy for old systems. Should be deprecated at some point
# soon.
# - POWER7 (enabled via AT_PLATFORM)
# - Existing deployments.
# - POWER8 (enabled via AT_PLATFORM)
# - Latest generation.
# 64-bit LE:
# - POWER8 LE (default)
# - Latest generation.
Whatever decisions you make, please tell us and we can adjust the
library.
sorry for the late reply, but Fedora PPC team would like keep the
support for Power7 for a while until we will able to replace the
remaining older HW with Power8 one. We have already started the required
actions, but as you can understand it will take some time. I personally
expect we will be able to switch F-25 to pure Power8.
We do not recommend the users to anything else then Power8, that's why
the "supported" state for Power8 in the wiki.
64-bit BE - sounds good
64-bit LE - please add back the Power7 support, and keep the Power8
optimized one, so users can take advantage of their hw
Thanks
Dan