[PATCH v3] ci: support Travis CI's aarch64 builds

[Paul Chaignon]

On Thu, Nov 14, 2019 at 10:20:50PM +0300, Dmitry V. Levin wrote:
> On Thu, Nov 14, 2019 at 06:37:10PM +0100, Paul Chaignon wrote:
> > Travis CI now supports aarch64 builds, launched with the new "arch: arm64"
> > tag.  These builds are running inside LXD only for the moment.
> > 
> > The aarch64 builds tend to be a lot slower than their x86_64 counterparts,
> > so several timeout values need to be increased.  I've also noticed a
> > smaller performance gain in filter_seccomp-perf.test for some builds.
> > 
> > Some tests occasionally take more than 10 minutes, hitting Travis CI's
> > limit on output inactivity.  Using "travis_wait 40" removes that limit for
> > 40 minutes (I've not seen any build last more 40 minutes).
> 
> It's not quite clear from Travis CI documentation [1] whether
> "travis_wait 40" extends the "no output timeout" by extra 40 minutes
> or it extends the timeout to 40 minutes.

If I understand the documentation correctly, it's neither: "travis_wait X"
gives us X minutes during which the "no output timeout" doesn't apply,
because a background process is writing to the build logs every minute.
If "travis_wait X" was simply extending the "no output timeout" from 10 to
X, then we could choose a value lower than 40 (because it's unlikely that
any single test actually takes 40 minutes).

I tried using "travis_wait 25", with the same "no output" error.  That's
because, after the 25 minutes grace period, a test ended up taking more
than 10 minutes.

> 
> By the way, there is another build timeout described in Travis CI
> documentation [2]: build job is terminated when it takes longer than 50
> minutes.
> 
> I've actually seen this 50 minutes timeout in strace builds when I tried
> to update Travis CI configuration from Trusty to Xenial [3] or Bionic [4].

It doesn't look like we can extend the 50 minutes timeout :(
Any idea why the builds take longer under Xenial and Bionic?

> 
> [1] https://docs.travis-ci.com/user/common-build-problems/#build-times-out-because-no-output-was-received
> [2] https://docs.travis-ci.com/user/customizing-the-build/#build-timeouts
> [3] https://travis-ci.org/strace/strace/builds/603208391
> [4] https://travis-ci.org/strace/strace/builds/603257898
> 
> 
> -- 
> ldv