
Towards parallel kernel test runs - sohkamyung
https://people.kernel.org/metan/towards-parallel-kernel-test-runs
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joosters
Is it really worth optimising the test runs in this way? The potential for
making a mistake in the test resource specifications is huge.

Sure, you might save a few minutes per test run, but at the cost of buggy,
unreproducible tests that fail at random due to interactions with other ones
running in parallel. Tests need to be reliable and developers need confidence
that the tests work and that failures are real.

~~~
setr
I can't imagine it being _that_ difficult to verify correctness of the changes
-- just compare the results of the original test suite, and the results of the
parallel one -- and try this repeatedly until you're confident you've avoided
any missed specifications

If the parallelism actually speeds things up, repeated runs shouldn't be too
painful :-)

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myroon5
"The naive solution is obviously to run $NCPU+1 tests in parallel. But there
is a catch, some of the tests utilize global system resources or state and
running two such tests in parallel would lead to false negatives."

Couldn't multiple test environments run even these tests in parallel?

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setheron
Why doesn't Linux tests auto run in qemu or even UML. UML sounds perfect for
unit testing the kernel without having to install it. I feel like there's a
chance to narrow the gap in a lot of CICD practices missing in the kernel.

~~~
amluto
UML is different enough than normal Linux to make this have dubious value.

KVM is fast. I personally test with virtme, but I haven’t set things up to
automatically run the selftest suite.

[https://github.com/amluto/virtme](https://github.com/amluto/virtme)

