On 24/09/19 23:46, Andrea Arcangeli wrote: >>> >>> I would keep only EXIT_REASON_MSR_WRITE, EXIT_REASON_PREEMPTION_TIMER, >>> EXIT_REASON_EPT_MISCONFIG and add EXIT_REASON_IO_INSTRUCTION. >> Intuition doesn't work great when it comes to CPU speculative >> execution runtime. I can however run additional benchmarks to verify >> your theory that keeping around frequent retpolines will still perform >> ok. > On one most recent CPU model there's no measurable difference with > your list or my list with a hrtimer workload (no cpuid). It's > challenging to measure any difference below 0.5%. Let's keep the short list then. Paolo
