/* * pmap_load: perform the actual pmap switch, i.e. fill in %cr3 register * and relevant LDT info. * * Ensures that the current process' pmap is loaded on the current CPU's * MMU and that there are no stale TLB entries. * * => The caller should disable kernel preemption or do check-and-retry * to prevent a preemption from undoing our efforts. * => This function may block. */