+ /*
+ * Cede if the other thread is not idle, so that it can
+ * go single-threaded. If the other thread is idle,
+ * we ask the hypervisor if it has pending work it
+ * wants to do and cede if it does. Otherwise we keep
+ * polling in order to reduce interrupt latency.
+ *
+ * Doing the cede when the other thread is active will
+ * result in this thread going dormant, meaning the other
+ * thread gets to run in single-threaded (ST) mode, which
+ * is slightly faster than SMT mode with this thread at
+ * very low priority. The cede enables interrupts, which
+ * doesn't matter here.
+ */
+ if (!lppaca[cpu ^ 1].idle || poll_pending() == H_PENDING)
+ cede_processor();