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If >> the primary thread is offlined and secondary thread is not >> considered, we will miss/skip setting either the RMPOPT_BASE MSR or >> not issuing the RMPOPT instruction for that physical CPU, which >> means no RMP optimizations enabled for that physical CPU. > What is the harm of issuing it twice per core? Why to issue it if we can avoid it. It is not that complex to setup a cpumask containing the online primary or secondary thread and then issue the RMPOPT instruction only once per thread. Thanks, Ashish