Once upon a time, Bill Nottingham <notting@xxxxxxxxxx> said: > Why? > > - We don't really support i586 in any meaningful matter What does this mean? Does Fedora not run on i586? Why was there a mass-rebuild for i586 if it doesn't work? > - We are likely doing a mass rebuild for F-12 anyways, might as well switch > while we're doing it That's a pretty poor justification. > - Atom is the only currently produced 32-bit x86 chip of note; optimize > for what's currently available There are also lots of other chips that people run 32 bit x86 code on. I don't think Atom is a majority percentage of 32 bix x86 Fedora users either. > If you want numbers, I did some benchmarking of code [1] with various > build options on a variety of processors, with the F-11 gcc code. All > of these results are relative to a F-11 baseline of "-march=i586 > -mtune=generic". > > P4 2.4Ghz Athlon 3400+ Core2Duo E6850 Atom N270 > march=i686/ -1.1% +2.0% +0.9% +0.6% > mtune=generic > march=i586/ +0.3% -0.3% -0.2% +1.3% > mtune=atom > march=i686/ -1.5% +1.2% +0.5% +1.7% > mtune=atom > > Bill > > [1] gzip, bzip2, math simulation, mp3 encode/decode, ogg encode/decode Okay, before I thought you said this was a "1-2% improvement across the board", but now it is a 1% improvement on some CPU-intensive operations on some CPUs (and a 1% performance hit on other CPUs). How does this affect multilib on x86_64? The justification for the i586 rebuild was that there hasn't been a Fedora i386 kernel for years (so i586 was already required anyway). This is the first time Fedora is proposing to throw out CPU support in a long long time, and I find a minimal improvement on some targeted benchmarks a poor justification. It would seem to me that adding a few targeted Atom packages would be a better use of resources (e.g. similar to openssl.i686). -- Chris Adams <cmadams@xxxxxxxxxx> Systems and Network Administrator - HiWAAY Internet Services I don't speak for anybody but myself - that's enough trouble. -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
