Re: [PATCH 4/4] selftests/sgx: Trigger the reclaimer and #PF handler

From: Dave Hansen
Date: Wed Jul 07 2021 - 17:20:12 EST

On 7/7/21 1:50 PM, Jarkko Sakkinen wrote:
> There is consistent known behaviour how reclaimer and also the page fault
> are exercised for each test. I think that is what matters most right now
> that the basic behaviour of both the page reclaimer and page fault handler
> gets exercised.

There's also a lot of value to ensuring that tests can run _quickly_.
If you have a test that fails one out of a million executions, it's a
lot easier find and debug if it takes 1 ms versus 10 seconds.

In other words, I think I'd prefer if we run two enclaves in each
execution of the selftest. One can be as small as possible. The other
can be the reclaim-triggering one.

That's good both for test coverage, and it makes it a *bit* more
straightforward to hack out the reclaim test if you need things to run

The pkeys selftest isn't a bad example here either. It has a couple of
different "malloc()" options: THP, hugetlbfs, small-page mmap(), and a
bunch of tests it runs on each type. As we add more SGX tests, we might
end up with "do reclaim" just being an option we pass.