Re: Restraining poudriere

From: bob prohaska <fbsd_at_www.zefox.net>
Date: Sat, 12 Jun 2021 23:16:44 UTC
On Sat, Jun 12, 2021 at 01:26:16PM -0700, Jose Quinteiro wrote:
> On 6/12/21 10:57 AM, bob prohaska wrote:
> > 
> > Trying it now, hoping to see parallel core use.
> 
> You won't. Setting PARALLEL_JOBS=1 means exactly one Poudriere worker
> will run, and that make will not build in parallel. You have to decide
> whether you want multiple Poudriere jobs, each using a single core at
> most, one Poudriere job with make(1) potentially using several cores, or
> some combination of both.
> 
> The three variables that control this are:
> 
> PARALLEL_JOBS, as you already know. This is the maximum number of
> workers Poudriere will launch. It can be less than this if there are
> multiple dependent packages waiting for a big package to build. This
> happens a lot with Llvm and the like. Not having ALLOW_MAKE_JOBS set is
> very frustrating in this case, because the big pig of a build will use
> one core at most and take forever.
> 
> ALLOW_MAKE_JOBS and MAKE_JOBS_NUMBER (make.conf). The first one allows
> make(1) to launch parallel jobs, and the second controls the maximum
> number of make jobs that will be launched. The problem here is that many
> builds have lengthy steps that are not concurrent (I'm looking at you,
> autotools!) A lot of times the actual compile and link steps take a tiny
> fraction of the total build time.
> 
> I chose to use a combination of both, and had to experiment with
> different numbers for PARALLEL_JOBS mad MAKE_JOBS_NUMBER so that a
> majority of my cores were used for the build, but I did not run out of
> memory:
> https://forums.FreeBSD.org/threads/poudriere-never-completes-first-run-without-errors.78000/post-486707
> 

It appears that starting poudriere with -J 1 and adding
ALLOW_MAKE_JOBS=yes
MAKE_JOBS_NUMBER=4
to /etc/make.conf will come a little closer to making good use
of the machine's puny resources. Have I got that right?

It also looks as if setting 
USE_TMPFS=no
in /usr/local/etc/poudriere.conf will help. Right now, with
tmpfs enabled on a single thread the machine is using 800 MB
of swap. 

I rather like your idea of setting a target load average. 
Wish I knew how to do it...... methinks it isn't simple.

Thanks again!

bob prohaska