Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (9e79c523) · Commits · 戴 / test

kernel/cpu.c

+72 −71

Original line number	Diff line number	Diff line
		@@ -1909,6 +1909,78 @@ void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
		}
		EXPORT_SYMBOL(__cpuhp_remove_state);

		#ifdef CONFIG_HOTPLUG_SMT
		static void cpuhp_offline_cpu_device(unsigned int cpu)
		{
		struct device *dev = get_cpu_device(cpu);

		dev->offline = true;
		/* Tell user space about the state change */
		kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
		}

		static void cpuhp_online_cpu_device(unsigned int cpu)
		{
		struct device *dev = get_cpu_device(cpu);

		dev->offline = false;
		/* Tell user space about the state change */
		kobject_uevent(&dev->kobj, KOBJ_ONLINE);
		}

		int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
		{
		int cpu, ret = 0;

		cpu_maps_update_begin();
		for_each_online_cpu(cpu) {
		if (topology_is_primary_thread(cpu))
		continue;
		ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
		if (ret)
		break;
		/*
		* As this needs to hold the cpu maps lock it's impossible
		* to call device_offline() because that ends up calling
		* cpu_down() which takes cpu maps lock. cpu maps lock
		* needs to be held as this might race against in kernel
		* abusers of the hotplug machinery (thermal management).
		*
		* So nothing would update device:offline state. That would
		* leave the sysfs entry stale and prevent onlining after
		* smt control has been changed to 'off' again. This is
		* called under the sysfs hotplug lock, so it is properly
		* serialized against the regular offline usage.
		*/
		cpuhp_offline_cpu_device(cpu);
		}
		if (!ret)
		cpu_smt_control = ctrlval;
		cpu_maps_update_done();
		return ret;
		}

		int cpuhp_smt_enable(void)
		{
		int cpu, ret = 0;

		cpu_maps_update_begin();
		cpu_smt_control = CPU_SMT_ENABLED;
		for_each_present_cpu(cpu) {
		/* Skip online CPUs and CPUs on offline nodes */
		if (cpu_online(cpu) \|\| !node_online(cpu_to_node(cpu)))
		continue;
		ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
		if (ret)
		break;
		/* See comment in cpuhp_smt_disable() */
		cpuhp_online_cpu_device(cpu);
		}
		cpu_maps_update_done();
		return ret;
		}
		#endif

		#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
		static ssize_t show_cpuhp_state(struct device *dev,
		struct device_attribute attr, char buf)
		@@ -2063,77 +2135,6 @@ static const struct attribute_group cpuhp_cpu_root_attr_group = {

		#ifdef CONFIG_HOTPLUG_SMT

		static void cpuhp_offline_cpu_device(unsigned int cpu)
		{
		struct device *dev = get_cpu_device(cpu);

		dev->offline = true;
		/* Tell user space about the state change */
		kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
		}

		static void cpuhp_online_cpu_device(unsigned int cpu)
		{
		struct device *dev = get_cpu_device(cpu);

		dev->offline = false;
		/* Tell user space about the state change */
		kobject_uevent(&dev->kobj, KOBJ_ONLINE);
		}

		int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
		{
		int cpu, ret = 0;

		cpu_maps_update_begin();
		for_each_online_cpu(cpu) {
		if (topology_is_primary_thread(cpu))
		continue;
		ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
		if (ret)
		break;
		/*
		* As this needs to hold the cpu maps lock it's impossible
		* to call device_offline() because that ends up calling
		* cpu_down() which takes cpu maps lock. cpu maps lock
		* needs to be held as this might race against in kernel
		* abusers of the hotplug machinery (thermal management).
		*
		* So nothing would update device:offline state. That would
		* leave the sysfs entry stale and prevent onlining after
		* smt control has been changed to 'off' again. This is
		* called under the sysfs hotplug lock, so it is properly
		* serialized against the regular offline usage.
		*/
		cpuhp_offline_cpu_device(cpu);
		}
		if (!ret)
		cpu_smt_control = ctrlval;
		cpu_maps_update_done();
		return ret;
		}

		int cpuhp_smt_enable(void)
		{
		int cpu, ret = 0;

		cpu_maps_update_begin();
		cpu_smt_control = CPU_SMT_ENABLED;
		for_each_present_cpu(cpu) {
		/* Skip online CPUs and CPUs on offline nodes */
		if (cpu_online(cpu) \|\| !node_online(cpu_to_node(cpu)))
		continue;
		ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
		if (ret)
		break;
		/* See comment in cpuhp_smt_disable() */
		cpuhp_online_cpu_device(cpu);
		}
		cpu_maps_update_done();
		return ret;
		}


		static ssize_t
		__store_smt_control(struct device dev, struct device_attribute attr,
		const char *buf, size_t count)

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