30.4.4.8 The ps_setup_enable_background_threads() Procedure
Enables Performance Schema instrumentation for all background
threads. Produces a result set indicating how many background
threads were enabled. Already enabled threads do not count.
mysql> CALL sys.ps_setup_enable_background_threads();
+-------------------------------+
| summary |
+-------------------------------+
| Enabled 24 background threads |
+-------------------------------+