- /* Lockless receive, part 2:
- * Wait until pipelined_send or expunge_all are outside of
- * wake_up_process(). There is a race with exit(), see
- * ipc/mqueue.c for the details. The correct serialization
- * ensures that a receiver cannot continue without the wakeup
- * being visibible _before_ setting r_msg:
- *
- * CPU 0 CPU 1
- * <loop receiver>
- * smp_rmb(); (A) <-- pair -. <waker thread>
- * <load ->r_msg> | msr->r_msg = NULL;
- * | wake_up_process();
- * <continue> `------> smp_wmb(); (B)
- * msr->r_msg = msg;
+ /*
+ * Lockless receive, part 2:
+ * The work in pipelined_send() and expunge_all():
+ * - Set pointer to message
+ * - Queue the receiver task for later wakeup
+ * - Wake up the process after the lock is dropped.