Buildworld and buildkernel with very slow compilation, recently

[Donald Wilde]

On 6/22/20, Eugene Grosbein <eugen at grosbein.net> wrote:
> 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 :-)

Eugene, I have noticed  (though quite anecdotally) a real slowdown, so
I'd like to help.

My mule is not busy at this time so if you have a place to put these
output files, I'll be glad to crunch some over the next few days. My
mule is only an i3 with 4GB with 40G of swap and an active ccache, but
I should be able to run any variant of tests you need to see. I'm on
12-STABLE and I now am doing a fresh base/stable/12 pull. I have _not_
deleted my /usr/src.bak copy, although I didn't stash a copy of the
old ports tree before updating it.

I use tcsh everywhere, but I should be able to do what you intend
(hey, it's been a loooong time since I tried to speak csh!) and if
you'd like me to do deltas with LLVM80 vs LLVM90 vs. LLVM100, etc, I
can do this. Just tell me exactly what you want to see.
-- 
Don Wilde
****************************************************
* What is the Internet of Things but a system *
* of systems including humans?                     *
****************************************************