--- zzzz-none-000/linux-4.4.271/Documentation/timers/timers-howto.txt	2021-06-03 06:22:09.000000000 +0000
+++ hawkeye-5590-750/linux-4.4.271/Documentation/timers/timers-howto.txt	2023-04-19 10:22:27.000000000 +0000
@@ -103,3 +103,6 @@
 			short, the difference is whether the sleep can be ended
 			early by a signal. In general, just use msleep unless
 			you know you have a need for the interruptible variant.
+
+	FLEXIBLE SLEEPING (any delay, uninterruptible)
+		* Use fsleep