+ /*
+ * pthread_kill has a smp_mb(). But beware, we assume it performs
+ * a cache flush on architectures with non-coherent cache. Let's play
+ * safe and don't assume anything : we use smp_mc() to make sure the
+ * cache flush is enforced.
+ * smp_mb(); write sig_done before sending the signals
+ */
+ smp_mc(); /* write sig_done before sending the signals */