smp/cfd: Convert core to hotplug state machine (31487f83) · Commits · 戴 / test

include/linux/cpuhotplug.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@ enum cpuhp_state {
		CPUHP_HRTIMERS_PREPARE,
		CPUHP_PROFILE_PREPARE,
		CPUHP_X2APIC_PREPARE,
		CPUHP_SMPCFD_PREPARE,
		CPUHP_TIMERS_DEAD,
		CPUHP_NOTIFY_PREPARE,
		CPUHP_BRINGUP_CPU,
		@@ -57,6 +58,7 @@ enum cpuhp_state {
		CPUHP_AP_ARM_CORESIGHT4_STARTING,
		CPUHP_AP_ARM64_ISNDEP_STARTING,
		CPUHP_AP_LEDTRIG_STARTING,
		CPUHP_AP_SMPCFD_DYING,
		CPUHP_AP_X86_TBOOT_DYING,
		CPUHP_AP_NOTIFY_STARTING,
		CPUHP_AP_ONLINE,

include/linux/smp.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -196,4 +196,9 @@ extern void arch_enable_nonboot_cpus_end(void);

		void smp_setup_processor_id(void);

		/* SMP core functions */
		int smpcfd_prepare_cpu(unsigned int cpu);
		int smpcfd_dead_cpu(unsigned int cpu);
		int smpcfd_dying_cpu(unsigned int cpu);

		#endif /* __LINUX_SMP_H */

kernel/cpu.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -1195,6 +1195,11 @@ static struct cpuhp_step cpuhp_bp_states[] = {
		.startup = hrtimers_prepare_cpu,
		.teardown = hrtimers_dead_cpu,
		},
		[CPUHP_SMPCFD_PREPARE] = {
		.name = "SMPCFD prepare",
		.startup = smpcfd_prepare_cpu,
		.teardown = smpcfd_dead_cpu,
		},
		[CPUHP_TIMERS_DEAD] = {
		.name = "timers dead",
		.startup = NULL,
		@@ -1218,6 +1223,10 @@ static struct cpuhp_step cpuhp_bp_states[] = {
		.teardown = NULL,
		.cant_stop = true,
		},
		[CPUHP_AP_SMPCFD_DYING] = {
		.startup = NULL,
		.teardown = smpcfd_dying_cpu,
		},
		/*
		* Handled on controll processor until the plugged processor manages
		* this itself.

kernel/smp.c

+32 −47

Original line number	Diff line number	Diff line
		@@ -33,38 +33,33 @@ static DEFINE_PER_CPU_SHARED_ALIGNED(struct llist_head, call_single_queue);

		static void flush_smp_call_function_queue(bool warn_cpu_offline);

		static int
		hotplug_cfd(struct notifier_block nfb, unsigned long action, void hcpu)
		int smpcfd_prepare_cpu(unsigned int cpu)
		{
		long cpu = (long)hcpu;
		struct call_function_data *cfd = &per_cpu(cfd_data, cpu);

		switch (action) {
		case CPU_UP_PREPARE:
		case CPU_UP_PREPARE_FROZEN:
		if (!zalloc_cpumask_var_node(&cfd->cpumask, GFP_KERNEL,
		cpu_to_node(cpu)))
		return notifier_from_errno(-ENOMEM);
		return -ENOMEM;
		cfd->csd = alloc_percpu(struct call_single_data);
		if (!cfd->csd) {
		free_cpumask_var(cfd->cpumask);
		return notifier_from_errno(-ENOMEM);
		return -ENOMEM;
		}

		return 0;
		}
		break;

		#ifdef CONFIG_HOTPLUG_CPU
		case CPU_UP_CANCELED:
		case CPU_UP_CANCELED_FROZEN:
		/* Fall-through to the CPU_DEAD[_FROZEN] case. */
		int smpcfd_dead_cpu(unsigned int cpu)
		{
		struct call_function_data *cfd = &per_cpu(cfd_data, cpu);

		case CPU_DEAD:
		case CPU_DEAD_FROZEN:
		free_cpumask_var(cfd->cpumask);
		free_percpu(cfd->csd);
		break;
		return 0;
		}

		case CPU_DYING:
		case CPU_DYING_FROZEN:
		int smpcfd_dying_cpu(unsigned int cpu)
		{
		/*
		* The IPIs for the smp-call-function callbacks queued by other
		* CPUs might arrive late, either due to hardware latencies or
		@@ -75,27 +70,17 @@ hotplug_cfd(struct notifier_block nfb, unsigned long action, void hcpu)
		* still pending.
		*/
		flush_smp_call_function_queue(false);
		break;
		#endif
		};

		return NOTIFY_OK;
		return 0;
		}

		static struct notifier_block hotplug_cfd_notifier = {
		.notifier_call = hotplug_cfd,
		};

		void __init call_function_init(void)
		{
		void cpu = (void )(long)smp_processor_id();
		int i;

		for_each_possible_cpu(i)
		init_llist_head(&per_cpu(call_single_queue, i));

		hotplug_cfd(&hotplug_cfd_notifier, CPU_UP_PREPARE, cpu);
		register_cpu_notifier(&hotplug_cfd_notifier);
		smpcfd_prepare_cpu(smp_processor_id());
		}

		/*

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