Injecting faults into the kernel [LWN.net]

Injecting faults into the kernel

Posted Nov 16, 2006 10:51 UTC (Thu) by mokki (subscriber, #33200)
In reply to: Injecting faults into the kernel by simlo
Parent article: Injecting faults into the kernel

I do agree that unit tests would be the way to go in an ideal world.

But in the real world there will always be code in the kernel that is not fully covered by unit tests (and even 100% coverage does not guarantee anything).

What this fault injection provides is a way to third parties to test the whole system or partial system failures independently. I think such a feature can only be helpful and does not prevent in any way applying of any other testing methods.

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Injecting faults into the kernel vs unit testing

Posted Nov 17, 2006 23:19 UTC (Fri) by giraffedata (subscriber, #1954) [Link]

I think the main value of this fault injection over unit testing is cost. It takes a significant amount of time and boredom to write scaffolding for a module of the kernel, but a complete scaffold already exists -- the rest of the real kernel. All it lacks is the controls to manipulate all the inputs and outputs to get a full test, so fault injection adds a faint whisper of those.

I too agree that unit testing (and modular programming in general) gives a better result. But I understand why people find it not worth the cost.