[libvirt PATCH] ci: maximize cirrus CI ram/cpu allocation

[Andrea Bolognani]

On Wed, Jul 21, 2021 at 12:06:35PM +0100, Daniel P. Berrangé wrote:
> On Wed, Jul 21, 2021 at 11:48:17AM +0100, Daniel P. Berrangé wrote:
> > Thus I'm really puzzelled why libvirt didn't see a real benefit
> > when I tested it.  As you say though, FreeBSD builds are no worse
> > than Linux builds, so it isn't critical for us.
>
> I guess looking at the CPU chart in this run explains it:
>
>   https://cirrus-ci.com/task/5496170802839552
>
> The first 75% of the job time was using less than 1 CPU. Only
> the last 3 minutes maxed out both CPUs. So adding more CPUS
> will only help the last bit of the job and even then we'll
> hit limits on amount of parallelism due to build dependancies.
>
> QEMU simply has much much more stuff needing building and is
> highly parallel when building, so saw a big benefit.
>
> So this affirms that we dont really need this patch.

We could still spell out our expectations in term of resource
allocation, and just set 4 CPUs / 2 GiB of RAM across the board. I
think that would be still moderately useful, for documentation
purposes if nothing else, and might help Cirrus CI better distribute
its computing resources among users.

We don't even need to make it dynamic per job, we can just hardcode
those values in ci/cirrus/build.yml and call it a day.

-- 
Andrea Bolognani / Red Hat / Virtualization