linux/drivers/cpuidle/governors
Rafael J. Wysocki 87c9fe6ee4 cpuidle: menu: Avoid selecting shallow states with stopped tick
If the scheduler tick has been stopped already and the governor
selects a shallow idle state, the CPU can spend a long time in that
state if the selection is based on an inaccurate prediction of idle
time.  That effect turns out to be relevant, so it needs to be
mitigated.

To that end, modify the menu governor to discard the result of the
idle time prediction if the tick is stopped and the predicted idle
time is less than the tick period length, unless the tick timer is
going to expire soon.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2018-04-09 11:54:57 +02:00
..
Makefile cpuidle: consolidate 2.6.22 cpuidle branch into one patch 2007-10-10 00:12:41 -04:00
ladder.c cpuidle: Return nohz hint from cpuidle_select() 2018-04-06 09:29:34 +02:00
menu.c cpuidle: menu: Avoid selecting shallow states with stopped tick 2018-04-09 11:54:57 +02:00