Re: [PATCH v2] .gitlab-ci.d/crossbuilds.yml: Force 'make check' single-threaded for cross-i686-tci

[Daniel P . Berrangé]

On Fri, Sep 13, 2024 at 02:31:34PM +0100, Peter Maydell wrote:
> On Fri, 13 Sept 2024 at 13:24, Peter Maydell <peter.maydell@linaro.org> wrote:
> >
> > On Thu, 12 Sept 2024 at 16:10, Peter Maydell <peter.maydell@linaro.org> 
> > wrote:
> > >
> > > The cross-i686-tci CI job is persistently flaky with various tests
> > > hitting timeouts.  One theory for why this is happening is that we're
> > > running too many tests in parallel and so sometimes a test gets
> > > starved of CPU and isn't able to complete within the timeout.
> > >
> > > (The environment this CI job runs in seems to cause us to default
> > > to a parallelism of 9 in the main CI.)
> > >
> > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > > ---
> > > If this works we might be able to wind this up to -j2 or -j3,
> > > and/or consider whether other CI jobs need something similar.
> >
> > I gave this a try, but unfortunately the result seems to be
> > that the whole job times out:
> > https://gitlab.com/qemu-project/qemu/-/jobs/7818441897
> 
> ...but then this simple retry passed with a runtime of 47 mins:
> 
> https://gitlab.com/qemu-project/qemu/-/jobs/7819225200
> 
> I'm tempted to commit this as-is, and see whether it helps.
> If it doesn't I can always back it off to -j2, and if it does
> generate a lot of full-job-timeouts it's only me it's annoying.

Anyone know how many vCPUs our k8s runners have ?

The gitlab runners that contributor forks use will have 2
vCPUs. So our current make -j$(nproc+1)  will be effectively
-j3 already in pipelines for forks. IOW, we intentionally
slightly over-commit CPUs right now. Backing off to just
-j$(nproc)  may be better than hardcoding -j1/-j2, so that
it takes account of different runner sizes ?


With regards,
Daniel
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