On Thu, Jun 30, 2016 at 12:12:37PM +0200, Dan Horák wrote: > For ppc64 (the big endian POWER) the base is set by the toolchain > default which is Power4/ppc970. When Power7 came we were asked what are > the options to take the advantage of these CPUs, 3 generations newer > than the base. The solution was the introduction of ppc64p7 subarch into > the packaging and release engineering tools. But it showed more as a > hack than a solution, touching rpm, yum, koji, .... The list of packages > is manually maintained, requires manual updates to the buildsystem for > new releases, seems new packaging tools (dnf) don't understand it > correctly. Is there a way to make the subarch mechanism generic and > integrated with the other tools? So we could have ppc64p8 and ppc64p9 > inside Fedora for POWER ... I will just snipe here that the situation would be better if POWER > 4 hardware was generally available to buy. > Now I'm getting to an area where others are the experts :-) Glibc > allows to build and install multiple per-cpu optimized runtimes that > are selected based on the CPU. There is the IFUNC mechanism and > function multi-versioning in GCC (user-friendly IFUNC) [2] to allow > multiple implementations inside one library/binary. Be careful with using IFUNC. It's a very desirable feature, implemented in a somewhat ill-defined way: https://bugzilla.redhat.com/show_bug.cgi?id=1312462#c22 https://bugzilla.redhat.com/show_bug.cgi?id=1312462#c27 etc. Have you looked at what Debian does with the /lib/<arch> directories? I think we should follow Debian if appropriate. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com libguestfs lets you edit virtual machines. Supports shell scripting, bindings from many languages. http://libguestfs.org -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://lists.fedoraproject.org/admin/lists/devel@xxxxxxxxxxxxxxxxxxxxxxx
