[Query]: tick-sched: can idle_active be false in tick_nohz_idle_exit()?

From: Viresh Kumar
Date: Wed Apr 09 2014 - 07:59:08 EST


Hi Guys,

File: kernel/time/tick-sched.c
function: tick_nohz_idle_exit()

We are checking here if idle_active is true or not and then
do some stuff. But is it possible that idle_active be false
here?

The sequence as far as I understood is:
idle-loop:

tick_nohz_idle_enter(), i.e. idle_active = true;
local_irq_disable()

IDLE
.
.

wake up due to IPI ??

local_irq_enable()
tick_nohz_irq_enter(), i.e. idle_active = false;
tick_nohz_irq_exit(), i.e. idle_active = true;

tick_nohz_idle_exit()

How can idle_active be false here?

--
viresh
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