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Commit 9cf7243d authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

sched: Make set_cpu_rq_start_time() a built in hotplug state 



Start distangling the maze of hotplug notifiers in the scheduler.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: rt@linutronix.de
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent e9d867a6

include/linux/cpuhotplug.h

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ enum cpuhp_state { 
	CPUHP_BRINGUP_CPU,

	CPUHP_AP_IDLE_DEAD,

	CPUHP_AP_OFFLINE,

	CPUHP_AP_SCHED_STARTING,

	CPUHP_AP_NOTIFY_STARTING,

	CPUHP_AP_ONLINE,

	CPUHP_TEARDOWN_CPU,

include/linux/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -372,6 +372,7 @@ extern void cpu_init (void); 
extern void trap_init(void);

extern void update_process_times(int user);

extern void scheduler_tick(void);

extern int sched_cpu_starting(unsigned int cpu);



extern void sched_show_task(struct task_struct *p);

kernel/cpu.c

+6 −0
Original line number Diff line number Diff line
@@ -1236,6 +1236,12 @@ static struct cpuhp_step cpuhp_ap_states[] = { 
		.name			= "ap:offline",

		.cant_stop		= true,

	},

	/* First state is scheduler control. Interrupts are disabled */

	[CPUHP_AP_SCHED_STARTING] = {

		.name			= "sched:starting",

		.startup		= sched_cpu_starting,

		.teardown		= NULL,

	},

	/*

	 * Low level startup/teardown notifiers. Run with interrupts

	 * disabled. Will be removed once the notifiers are converted to

kernel/sched/core.c

+9 −7
Original line number Diff line number Diff line
@@ -5473,10 +5473,10 @@ static struct notifier_block migration_notifier = { 
	.priority = CPU_PRI_MIGRATION,

};



static void set_cpu_rq_start_time(void)

static void set_cpu_rq_start_time(unsigned int cpu)

{

	int cpu = smp_processor_id();

	struct rq *rq = cpu_rq(cpu);



	rq->age_stamp = sched_clock_cpu(cpu);

}
@@ -5486,10 +5486,6 @@ static int sched_cpu_active(struct notifier_block *nfb, 
	int cpu = (long)hcpu;



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_STARTING:

		set_cpu_rq_start_time();

		return NOTIFY_OK;



	case CPU_DOWN_FAILED:

		set_cpu_active(cpu, true);

		return NOTIFY_OK;
@@ -5511,6 +5507,12 @@ static int sched_cpu_inactive(struct notifier_block *nfb, 
	}

}



int sched_cpu_starting(unsigned int cpu)

{

	set_cpu_rq_start_time(cpu);

	return 0;

}



static int __init migration_init(void)

{

	void *cpu = (void *)(long)smp_processor_id();
@@ -7426,7 +7428,7 @@ void __init sched_init(void) 
	if (cpu_isolated_map == NULL)

		zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);

	idle_thread_set_boot_cpu();

	set_cpu_rq_start_time();

	set_cpu_rq_start_time(smp_processor_id());

#endif

	init_sched_fair_class();