Index: mysql-5.7.4-m14/mysys/thr_mutex.c
===================================================================
--- mysql-5.7.4-m14.orig/mysys/thr_mutex.c
+++ mysql-5.7.4-m14/mysys/thr_mutex.c
@@ -400,9 +400,16 @@ int my_pthread_fastmutex_lock(my_pthread
 
     if (res != EBUSY)
       return res;
-
+#ifdef __powerpc__
+    /* Set low thread priority while spinning */
+    asm volatile ("or 1,1,1");
+#endif
     mutex_delay(maxdelay);
     maxdelay += park_rng(mp) * MY_PTHREAD_FASTMUTEX_DELAY + 1;
+#ifdef __powerpc__
+    /* return to normal thread priority after spinning */
+    asm volatile ("or 2,2,2");
+#endif
   }
   return pthread_mutex_lock(&mp->mutex);
 }