“QSort killer” in 51a3030b6a5b37adc64f59c6bd9b2e41d724f8ef was made for different median selection strategy and does not kill 3fff2aca6dd7912d3d2d5a23a441d0ccb979d045 (nor vice versa). Correct killer (that also checks correctness and waits less): [kill3.patch](/uploads/0b937bf36a4ef37c23a11273946517b8/kill3.patch)). I wanted to say that just making `HeapSort` `public` or `protected` and calling it directly would be more future-proof, until noticed you purposefully check timings.