+ /*
+ * Accurate vmstat updates require a RMW. On !PREEMPT_RT kernels,
+ * atomicity is provided by IRQs being disabled -- either explicitly
+ * or via local_lock_irq. On PREEMPT_RT, local_lock_irq only disables
+ * CPU migrations and preemption potentially corrupts a counter so
+ * disable preemption.
+ */
+ if (IS_ENABLED(CONFIG_PREEMPT_RT))
+ preempt_disable();
+