Buildworld and buildkernel with very slow compilation, recently

[Eugene Grosbein]

22.06.2020 3:56, Dimitry Andric wrote:

> One of the upstream problems is that there is not really any
> authoritative performance regression log being built up, so it is hard
> to see where such regressions were introduced. Somebody then has to
> spend a lot of time tracking down each and every regression, and then
> attempt to untangle it from the dozens of commits made around the same
> time. :)

Such project as FreeBSD could become valuable source of information to track such an issue
and it's easy to obtain, for example:

make buildworld 2>&1 | logger -t buildworld -p user.info

This generates timestamps for every line called in process with help of syslogd.
It should be easy to compare outputs obtained with same FreeBSD revision
but different clang versions, calculate time diffs and sort by diffs descending :-)

Same for ports builds, maybe even quicker.