On Wed, Nov 23 2022 at 11:23, Anna-Maria Behnsen wrote:

quoted

 /**
- * add_timer_on - start a timer on a particular CPU
- * @timer: the timer to be added
- * @cpu: the CPU to start it on
+ * add_timer_on - Start a timer on a particular CPU
+ * @timer:	The timer to be started
+ * @cpu:	The CPU to start it on
  *
- * This is not very scalable on SMP. Double adds are not possible.
+ * This can only operate on an inactive timer. Attempts to invoke this on
+ * an active timer are rejected with a warning.

This is also true for add_timer(). Is it possible to add this to
add_timer() function description and just referencing to add_timer()
function description in add_timer_on()? They behave the same, only
difference is the CPU where the timer is enqueued.

Indeed.