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Commit cf37b6b4 authored by Nicolas Pitre's avatar Nicolas Pitre Committed by Ingo Molnar
Browse files

sched/idle: Move cpu/idle.c to sched/idle.c 



Integration of cpuidle with the scheduler requires that the idle loop be
closely integrated with the scheduler proper. Moving cpu/idle.c into the
sched directory will allow for a smoother integration, and eliminate a
subdirectory which contained only one source file.

Signed-off-by: default avatarNicolas Pitre <nico@linaro.org>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.LFD.2.11.1401301102210.1652@knanqh.ubzr


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 16f8b05a

kernel/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -22,7 +22,6 @@ obj-y += sched/ 
obj-y += locking/

obj-y += power/

obj-y += printk/

obj-y += cpu/

obj-y += irq/

obj-y += rcu/

kernel/cpu/Makefile

deleted100644 → 0
+0 −1
Original line number Diff line number Diff line 
obj-y	= idle.o

kernel/sched/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ endif 


obj-y += core.o proc.o clock.o cputime.o

obj-y += idle_task.o fair.o rt.o deadline.o stop_task.o

obj-y += wait.o completion.o

obj-y += wait.o completion.o idle.o

obj-$(CONFIG_SMP) += cpupri.o cpudeadline.o

obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o

obj-$(CONFIG_SCHEDSTATS) += stats.o

kernel/sched/idle.c

0 → 100644
+144 −0
Original line number Diff line number Diff line 
/*

 * Generic entry point for the idle threads

 */

#include <linux/sched.h>

#include <linux/cpu.h>

#include <linux/cpuidle.h>

#include <linux/tick.h>

#include <linux/mm.h>

#include <linux/stackprotector.h>



#include <asm/tlb.h>



#include <trace/events/power.h>



static int __read_mostly cpu_idle_force_poll;



void cpu_idle_poll_ctrl(bool enable)

{

	if (enable) {

		cpu_idle_force_poll++;

	} else {

		cpu_idle_force_poll--;

		WARN_ON_ONCE(cpu_idle_force_poll < 0);

	}

}



#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP

static int __init cpu_idle_poll_setup(char *__unused)

{

	cpu_idle_force_poll = 1;

	return 1;

}

__setup("nohlt", cpu_idle_poll_setup);



static int __init cpu_idle_nopoll_setup(char *__unused)

{

	cpu_idle_force_poll = 0;

	return 1;

}

__setup("hlt", cpu_idle_nopoll_setup);

#endif



static inline int cpu_idle_poll(void)

{

	rcu_idle_enter();

	trace_cpu_idle_rcuidle(0, smp_processor_id());

	local_irq_enable();

	while (!tif_need_resched())

		cpu_relax();

	trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());

	rcu_idle_exit();

	return 1;

}



/* Weak implementations for optional arch specific functions */

void __weak arch_cpu_idle_prepare(void) { }

void __weak arch_cpu_idle_enter(void) { }

void __weak arch_cpu_idle_exit(void) { }

void __weak arch_cpu_idle_dead(void) { }

void __weak arch_cpu_idle(void)

{

	cpu_idle_force_poll = 1;

	local_irq_enable();

}



/*

 * Generic idle loop implementation

 */

static void cpu_idle_loop(void)

{

	while (1) {

		tick_nohz_idle_enter();



		while (!need_resched()) {

			check_pgt_cache();

			rmb();



			if (cpu_is_offline(smp_processor_id()))

				arch_cpu_idle_dead();



			local_irq_disable();

			arch_cpu_idle_enter();



			/*

			 * In poll mode we reenable interrupts and spin.

			 *

			 * Also if we detected in the wakeup from idle

			 * path that the tick broadcast device expired

			 * for us, we don't want to go deep idle as we

			 * know that the IPI is going to arrive right

			 * away

			 */

			if (cpu_idle_force_poll || tick_check_broadcast_expired()) {

				cpu_idle_poll();

			} else {

				if (!current_clr_polling_and_test()) {

					stop_critical_timings();

					rcu_idle_enter();

					if (cpuidle_idle_call())

						arch_cpu_idle();

					if (WARN_ON_ONCE(irqs_disabled()))

						local_irq_enable();

					rcu_idle_exit();

					start_critical_timings();

				} else {

					local_irq_enable();

				}

				__current_set_polling();

			}

			arch_cpu_idle_exit();

			/*

			 * We need to test and propagate the TIF_NEED_RESCHED

			 * bit here because we might not have send the

			 * reschedule IPI to idle tasks.

			 */

			if (tif_need_resched())

				set_preempt_need_resched();

		}

		tick_nohz_idle_exit();

		schedule_preempt_disabled();

	}

}



void cpu_startup_entry(enum cpuhp_state state)

{

	/*

	 * This #ifdef needs to die, but it's too late in the cycle to

	 * make this generic (arm and sh have never invoked the canary

	 * init for the non boot cpus!). Will be fixed in 3.11

	 */

#ifdef CONFIG_X86

	/*

	 * If we're the non-boot CPU, nothing set the stack canary up

	 * for us. The boot CPU already has it initialized but no harm

	 * in doing it again. This is a good place for updating it, as

	 * we wont ever return from this function (so the invalid

	 * canaries already on the stack wont ever trigger).

	 */

	boot_init_stack_canary();

#endif

	__current_set_polling();

	arch_cpu_idle_prepare();

	cpu_idle_loop();

}