diff --git a/todo b/todo
index 8e52db3..6b6f93b 100644
--- a/todo
+++ b/todo
@@ -2,3 +2,5 @@
   using shared_ptr.
 * Ensure that we comb through the current code and enforce the distinction
   between user errors and program exceptions.
+* Investigate using MONITOR/MWAIT for spinlocks to reduce busy-waiting
+  stress/power consumption. Look for a parallel on ARM.