sched/hotplug: Convert cpu_[in]active notifiers to state machine (40190a78) · Commits · 戴 / test

include/linux/cpu.h

+0 −12

Original line number	Original line	Diff line number	Diff line
	@@ -59,18 +59,6 @@ struct notifier_block;
	* CPU notifier priorities.		* CPU notifier priorities.
	*/		*/
	enum {		enum {
	/*
	* SCHED_ACTIVE marks a cpu which is coming up active during
	* CPU_ONLINE and CPU_DOWN_FAILED and must be the first notifier. Is
	* also cpuset according to cpu_active mask right after activating the
	* cpu. During CPU_DOWN_PREPARE, SCHED_INACTIVE reversed the operation.
	*
	* This ordering guarantees consistent cpu_active mask and
	* migration behavior to all cpu notifiers.
	*/
	CPU_PRI_SCHED_ACTIVE = INT_MAX,
	CPU_PRI_SCHED_INACTIVE = INT_MIN,

	/* migration should happen before other stuff but after perf */		/* migration should happen before other stuff but after perf */
	CPU_PRI_PERF = 20,		CPU_PRI_PERF = 20,
	CPU_PRI_MIGRATION = 10,		CPU_PRI_MIGRATION = 10,

include/linux/cpuhotplug.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -13,6 +13,7 @@ enum cpuhp_state {
	CPUHP_AP_ONLINE,		CPUHP_AP_ONLINE,
	CPUHP_TEARDOWN_CPU,		CPUHP_TEARDOWN_CPU,
	CPUHP_AP_ONLINE_IDLE,		CPUHP_AP_ONLINE_IDLE,
			CPUHP_AP_ACTIVE,
	CPUHP_AP_SMPBOOT_THREADS,		CPUHP_AP_SMPBOOT_THREADS,
	CPUHP_AP_NOTIFY_ONLINE,		CPUHP_AP_NOTIFY_ONLINE,
	CPUHP_AP_ONLINE_DYN,		CPUHP_AP_ONLINE_DYN,

include/linux/sched.h

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -373,6 +373,8 @@ extern void trap_init(void);
	extern void update_process_times(int user);		extern void update_process_times(int user);
	extern void scheduler_tick(void);		extern void scheduler_tick(void);
	extern int sched_cpu_starting(unsigned int cpu);		extern int sched_cpu_starting(unsigned int cpu);
			extern int sched_cpu_activate(unsigned int cpu);
			extern int sched_cpu_deactivate(unsigned int cpu);

	extern void sched_show_task(struct task_struct *p);		extern void sched_show_task(struct task_struct *p);

kernel/cpu.c

+6 −2

Original line number	Original line	Diff line number	Diff line
	@@ -923,8 +923,6 @@ void cpuhp_online_idle(enum cpuhp_state state)

	st->state = CPUHP_AP_ONLINE_IDLE;		st->state = CPUHP_AP_ONLINE_IDLE;

	/* The cpu is marked online, set it active now */
	set_cpu_active(cpu, true);
	/* Unpark the stopper thread and the hotplug thread of this cpu */		/* Unpark the stopper thread and the hotplug thread of this cpu */
	stop_machine_unpark(cpu);		stop_machine_unpark(cpu);
	kthread_unpark(st->thread);		kthread_unpark(st->thread);
	@@ -1259,6 +1257,12 @@ static struct cpuhp_step cpuhp_ap_states[] = {
	[CPUHP_AP_ONLINE] = {		[CPUHP_AP_ONLINE] = {
	.name = "ap:online",		.name = "ap:online",
	},		},
			/* First state is scheduler control. Interrupts are enabled */
			[CPUHP_AP_ACTIVE] = {
			.name = "sched:active",
			.startup = sched_cpu_activate,
			.teardown = sched_cpu_deactivate,
			},
	/* Handle smpboot threads park/unpark */		/* Handle smpboot threads park/unpark */
	[CPUHP_AP_SMPBOOT_THREADS] = {		[CPUHP_AP_SMPBOOT_THREADS] = {
	.name = "smpboot:threads",		.name = "smpboot:threads",

kernel/sched/core.c

+21 −46

Original line number	Original line	Diff line number	Diff line
	@@ -6634,9 +6634,6 @@ static void sched_domains_numa_masks_set(unsigned int cpu)
	int node = cpu_to_node(cpu);		int node = cpu_to_node(cpu);
	int i, j;		int i, j;

	if (!sched_smp_initialized)
	return;

	for (i = 0; i < sched_domains_numa_levels; i++) {		for (i = 0; i < sched_domains_numa_levels; i++) {
	for (j = 0; j < nr_node_ids; j++) {		for (j = 0; j < nr_node_ids; j++) {
	if (node_distance(j, node) <= sched_domains_numa_distance[i])		if (node_distance(j, node) <= sched_domains_numa_distance[i])
	@@ -6649,9 +6646,6 @@ static void sched_domains_numa_masks_clear(unsigned int cpu)
	{		{
	int i, j;		int i, j;

	if (!sched_smp_initialized)
	return;

	for (i = 0; i < sched_domains_numa_levels; i++) {		for (i = 0; i < sched_domains_numa_levels; i++) {
	for (j = 0; j < nr_node_ids; j++)		for (j = 0; j < nr_node_ids; j++)
	cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]);		cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]);
	@@ -7051,12 +7045,9 @@ static int num_cpus_frozen; /* used to mark begin/end of suspend/resume */
	* If we come here as part of a suspend/resume, don't touch cpusets because we		* If we come here as part of a suspend/resume, don't touch cpusets because we
	* want to restore it back to its original state upon resume anyway.		* want to restore it back to its original state upon resume anyway.
	*/		*/
	static void cpuset_cpu_active(bool frozen)		static void cpuset_cpu_active(void)
	{		{
	if (!sched_smp_initialized)		if (cpuhp_tasks_frozen) {
	return;

	if (frozen) {
	/*		/*
	* num_cpus_frozen tracks how many CPUs are involved in suspend		* num_cpus_frozen tracks how many CPUs are involved in suspend
	* resume sequence. As long as this is not the last online		* resume sequence. As long as this is not the last online
	@@ -7077,17 +7068,14 @@ static void cpuset_cpu_active(bool frozen)
	cpuset_update_active_cpus(true);		cpuset_update_active_cpus(true);
	}		}

	static int cpuset_cpu_inactive(unsigned int cpu, bool frozen)		static int cpuset_cpu_inactive(unsigned int cpu)
	{		{
	unsigned long flags;		unsigned long flags;
	struct dl_bw *dl_b;		struct dl_bw *dl_b;
	bool overflow;		bool overflow;
	int cpus;		int cpus;

	if (!sched_smp_initialized)		if (!cpuhp_tasks_frozen) {
	return 0;

	if (!frozen) {
	rcu_read_lock_sched();		rcu_read_lock_sched();
	dl_b = dl_bw_of(cpu);		dl_b = dl_bw_of(cpu);

	@@ -7108,42 +7096,33 @@ static int cpuset_cpu_inactive(unsigned int cpu, bool frozen)
	return 0;		return 0;
	}		}

	static int sched_cpu_active(struct notifier_block *nfb, unsigned long action,		int sched_cpu_activate(unsigned int cpu)
	void *hcpu)
	{		{
	unsigned int cpu = (unsigned long)hcpu;

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_DOWN_FAILED:
	case CPU_ONLINE:
	set_cpu_active(cpu, true);		set_cpu_active(cpu, true);

			if (sched_smp_initialized) {
	sched_domains_numa_masks_set(cpu);		sched_domains_numa_masks_set(cpu);
	cpuset_cpu_active(action & CPU_TASKS_FROZEN);		cpuset_cpu_active();
	return NOTIFY_OK;
	default:
	return NOTIFY_DONE;
	}		}
			return 0;
	}		}

	static int sched_cpu_inactive(struct notifier_block *nfb,		int sched_cpu_deactivate(unsigned int cpu)
	unsigned long action, void *hcpu)
	{		{
	unsigned int cpu = (unsigned long)hcpu;
	int ret;		int ret;

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_DOWN_PREPARE:
	set_cpu_active(cpu, false);		set_cpu_active(cpu, false);
	ret = cpuset_cpu_inactive(cpu, action & CPU_TASKS_FROZEN);
			if (!sched_smp_initialized)
			return 0;

			ret = cpuset_cpu_inactive(cpu);
	if (ret) {		if (ret) {
	set_cpu_active(cpu, true);		set_cpu_active(cpu, true);
	return notifier_from_errno(ret);		return ret;
	}		}
	sched_domains_numa_masks_clear(cpu);		sched_domains_numa_masks_clear(cpu);
	return NOTIFY_OK;		return 0;
	default:
	return NOTIFY_DONE;
	}
	}		}

	int sched_cpu_starting(unsigned int cpu)		int sched_cpu_starting(unsigned int cpu)
	@@ -7197,10 +7176,6 @@ static int __init migration_init(void)
	migration_call(&migration_notifier, CPU_ONLINE, cpu);		migration_call(&migration_notifier, CPU_ONLINE, cpu);
	register_cpu_notifier(&migration_notifier);		register_cpu_notifier(&migration_notifier);

	/* Register cpu active notifiers */
	cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE);
	cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE);

	return 0;		return 0;
	}		}
	early_initcall(migration_init);		early_initcall(migration_init);

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