timers: Reduce future __run_timers() latency for first add to empty list
The __run_timers() function currently steps through the list one jiffy at
a time in order to update the timer wheel. However, if the timer wheel
is empty, no adjustment is needed other than updating ->timer_jiffies.
Therefore, just before we add a timer to an empty timer wheel, we should
mark the timer wheel as being up to date. This marking will reduce (and
perhaps eliminate) the jiffy-stepping that a future __run_timers() call
will need to do in response to some future timer posting or migration.
This commit therefore updates ->timer_jiffies for this case.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
1 file changed
