E (for AMD CPUs) which stops RDTSC on all currently known microarchitectures that implement SSE. On CPUs without SSE there is generally no RDTSC speculation. [ mingo@elte.hu: renamed it to rdtsc_barrier() and made it x86-only ] Signed-off-by: Andi Kleen Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner à‰