So I poked around at why ppc builds seem so slow. Net result: I still have no idea.

On a quad-970 machine with 2GiB of DRAM running the latest F-9, I did a 'make ppc64' build of the devel kernel with a modified kernel.spec file that spit out some basic timestamps on the RPM sections. Results:

Total time:

real 65m58.701s user 89m53.501s sys 11m4.737s

Each section:

Prep: 52 seconds Build: ~33 minutes Install: 38 seconds

[jwboyer@yoda devel]$ grep -e Prep -e Build -e Install .build-2.6.29-0.39.rc1.git5.fc11.log | grep -v + Building target platforms: ppc64 Building for target ppc64 Prep Start: Thu Jan 15 15:48:16 EST 2009 Prep End: Thu Jan 15 15:49:08 EST 2009 Build Start: Thu Jan 15 15:49:08 EST 2009 Build End: Thu Jan 15 16:22:57 EST 2009 Install Start: Thu Jan 15 16:22:57 EST 2009 Install End: Thu Jan 15 16:23:35 EST 2009

The overall time is slightly faster than the koji builds I've seen by a few minutes. This is somewhat expected, as my box wasn't really doing much else at the time and some of the builders are blades with fewer cores and slower hard drives.

Since I had nothing better to do in my sad life, I was watching the top output a bit during one of my builds. I noticed that when rpmbuild got to the part where it was writing out the -debuginfo RPM, it took almost 18 minutes. Why this is, I have no idea.

For gits and shiggles, I grabbed the config from the resulting RPM and used it with a 'time make -j4' on Linus' latest git tree:

real 28m46.829s user 70m30.520s sys 7m43.533s

So the build time seems roughly equivalent. Yay for doing stuff that garners no new insight!

josh