Re: [PATCH v2 4/5] KVM: selftests: Add a test for KVM_RUN+rseq to detect task migration bugs

----- On Aug 27, 2021, at 7:23 PM, Sean Christopherson seanjc@google.com wrote:

On Fri, Aug 27, 2021, Mathieu Desnoyers wrote:

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Does it reproduce if we randomize the delay to have it picked randomly from 0us to 100us (with 1us step) ? It would remove a lot of the needs for arch-specific magic delay value.

My less-than-scientific testing shows that it can reproduce at delays up to ~500us, but above ~10us the reproducibility starts to drop. The bug still reproduces reliably, it just takes more iterations, and obviously the test runs a bit slower.

Any objection to using a 1-10us delay, e.g. a simple usleep((i % 10) + 1)?

Works for me, thanks!

Mathieu