Re: [PATCH libevl 2/4] evl-test: run latmus in the end of the test suite

Tobias Schaffner <[email protected]> writes:

> Run latmus at the end of the session, before tearing down, to allow measuring
> the worst-case latency under load if a stress-command is given.
>
> Add --latmus-args to pass extra arguments to latmus (e.g. -A threshold or -T to
> override the runtime).
>
> latmus runs quietly for 10 seconds by default; a runtime passed through
> --latmus-args takes precedence. Its own output is dropped by default and
> can be redirected with --latmus-out.
>
> Examples:
>   # default: tests + a 10s latmus run, latmus output discarded
>   evl test
>
>   # fail if worst-case latency exceeds 150us
>   evl test --latmus-args "-A 150"
>
>   # measure latency under load for 60s, save the report
>   evl test --stress-cmd "stress-ng --cpu 4" \
>            --latmus-args "-T 60 -A 200" --latmus-out /tmp/latmus.log
>

The purpose is fine by me, but the integration logic looks too
complicated. Would it be possible to simply have a 'latency' test (as a
shell script) available from $libexec/evl/tests, that would launch the
latmus executable under the hood with the provided arguments?

Spawning it would amount to using the common syntax:

$ evl test latency [-- latmus-args ...]

With this, we could achieve the same goal with no addition required to
evl-test whatsoever:

$ evl test -k
$ evl test latency -- -A 150 -T 10s > /tmp/latmus.log

-- 
Philippe.