Commit b99a2659 authored by Qais Yousef's avatar Qais Yousef Committed by Thomas Gleixner
Browse files

cpu/hotplug: Move bringup of secondary CPUs out of smp_init() 



This is the last direct user of cpu_up() before it can become an internal
implementation detail of the cpu subsystem.

Signed-off-by: default avatarQais Yousef <qais.yousef@arm.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200323135110.30522-17-qais.yousef@arm.com
parent 457bc8ed

include/linux/cpu.h

+1 −0
Original line number Diff line number Diff line
@@ -94,6 +94,7 @@ void notify_cpu_starting(unsigned int cpu); 
extern void cpu_maps_update_begin(void);

extern void cpu_maps_update_done(void);

int bringup_hibernate_cpu(unsigned int sleep_cpu);

void bringup_nonboot_cpus(unsigned int setup_max_cpus);



#else	/* CONFIG_SMP */

#define cpuhp_tasks_frozen	0

kernel/cpu.c

+12 −0
Original line number Diff line number Diff line
@@ -1298,6 +1298,18 @@ int bringup_hibernate_cpu(unsigned int sleep_cpu) 
	return 0;

}



void bringup_nonboot_cpus(unsigned int setup_max_cpus)

{

	unsigned int cpu;



	for_each_present_cpu(cpu) {

		if (num_online_cpus() >= setup_max_cpus)

			break;

		if (!cpu_online(cpu))

			cpu_up(cpu);

	}

}



#ifdef CONFIG_PM_SLEEP_SMP

static cpumask_var_t frozen_cpus;

kernel/smp.c

+1 −8
Original line number Diff line number Diff line
@@ -597,20 +597,13 @@ void __init setup_nr_cpu_ids(void) 
void __init smp_init(void)

{

	int num_nodes, num_cpus;

	unsigned int cpu;



	idle_threads_init();

	cpuhp_threads_init();



	pr_info("Bringing up secondary CPUs ...\n");



	/* FIXME: This should be done in userspace --RR */

	for_each_present_cpu(cpu) {

		if (num_online_cpus() >= setup_max_cpus)

			break;

		if (!cpu_online(cpu))

			cpu_up(cpu);

	}

	bringup_nonboot_cpus(setup_max_cpus);



	num_nodes = num_online_nodes();

	num_cpus  = num_online_cpus();

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