Re: [PATCH 1/2] sched / idle: Drop default_idle_call() fallback from call_cpuidle()

From: Peter Zijlstra
Date: Mon Jan 18 2016 - 09:36:37 EST


On Sat, Jan 16, 2016 at 12:54:53AM +0100, Rafael J. Wysocki wrote:
> This eliminates one branch from the idle loop and makes the governors
> and find_deepest_state() handle the case when all states have been
> disabled from sysfs consistently.

> Index: linux-pm/kernel/sched/idle.c
> ===================================================================
> --- linux-pm.orig/kernel/sched/idle.c
> +++ linux-pm/kernel/sched/idle.c
> @@ -97,12 +97,6 @@ void default_idle_call(void)
> static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
> int next_state)
> {
> - /* Fall back to the default arch idle method on errors. */
> - if (next_state < 0) {
> - default_idle_call();
> - return next_state;
> - }
> -
> /*
> * The idle task must be scheduled, it is pointless to go to idle, just
> * update no idle residency and return.


Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>