On 2021/3/8 16:53, Peter Zijlstra wrote:
Still, it calling atomic_switch_perf_msrs() and intel_pmu_lbr_is_enabled() when there isn't a PMU at all is of course, a complete waste of cycles.
This suggestion is reminiscent of a sad regression of optimizing it: https://lore.kernel.org/kvm/[email protected]/ https://lore.kernel.org/kvm/[email protected]/
