Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu/SMT fix from Ingo Molnar: "Fix a build bug on CONFIG_HOTPLUG_SMT=y && !CONFIG_SYSFS kernels" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/SMT: Fix x86 link error without CONFIG_SYSFSalistair/sunxi64-5.5-dsi
Linus Torvalds
commit
9e79c52332
143
kernel/cpu.c
143
kernel/cpu.c
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@ -1909,6 +1909,78 @@ void __cpuhp_remove_state(enum cpuhp_state state, bool invoke)
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}
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EXPORT_SYMBOL(__cpuhp_remove_state);
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#ifdef CONFIG_HOTPLUG_SMT
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static void cpuhp_offline_cpu_device(unsigned int cpu)
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{
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struct device *dev = get_cpu_device(cpu);
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dev->offline = true;
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/* Tell user space about the state change */
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kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
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}
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static void cpuhp_online_cpu_device(unsigned int cpu)
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{
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struct device *dev = get_cpu_device(cpu);
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dev->offline = false;
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/* Tell user space about the state change */
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kobject_uevent(&dev->kobj, KOBJ_ONLINE);
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}
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int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
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{
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int cpu, ret = 0;
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cpu_maps_update_begin();
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for_each_online_cpu(cpu) {
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if (topology_is_primary_thread(cpu))
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continue;
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ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
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if (ret)
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break;
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/*
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* As this needs to hold the cpu maps lock it's impossible
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* to call device_offline() because that ends up calling
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* cpu_down() which takes cpu maps lock. cpu maps lock
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* needs to be held as this might race against in kernel
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* abusers of the hotplug machinery (thermal management).
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*
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* So nothing would update device:offline state. That would
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* leave the sysfs entry stale and prevent onlining after
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* smt control has been changed to 'off' again. This is
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* called under the sysfs hotplug lock, so it is properly
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* serialized against the regular offline usage.
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*/
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cpuhp_offline_cpu_device(cpu);
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}
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if (!ret)
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cpu_smt_control = ctrlval;
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cpu_maps_update_done();
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return ret;
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}
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int cpuhp_smt_enable(void)
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{
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int cpu, ret = 0;
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cpu_maps_update_begin();
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cpu_smt_control = CPU_SMT_ENABLED;
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for_each_present_cpu(cpu) {
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/* Skip online CPUs and CPUs on offline nodes */
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if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
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continue;
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ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
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if (ret)
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break;
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/* See comment in cpuhp_smt_disable() */
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cpuhp_online_cpu_device(cpu);
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}
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cpu_maps_update_done();
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return ret;
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}
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#endif
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#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU)
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static ssize_t show_cpuhp_state(struct device *dev,
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struct device_attribute *attr, char *buf)
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@ -2063,77 +2135,6 @@ static const struct attribute_group cpuhp_cpu_root_attr_group = {
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#ifdef CONFIG_HOTPLUG_SMT
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static void cpuhp_offline_cpu_device(unsigned int cpu)
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{
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struct device *dev = get_cpu_device(cpu);
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dev->offline = true;
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/* Tell user space about the state change */
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kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
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}
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static void cpuhp_online_cpu_device(unsigned int cpu)
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{
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struct device *dev = get_cpu_device(cpu);
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dev->offline = false;
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/* Tell user space about the state change */
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kobject_uevent(&dev->kobj, KOBJ_ONLINE);
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}
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int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval)
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{
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int cpu, ret = 0;
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cpu_maps_update_begin();
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for_each_online_cpu(cpu) {
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if (topology_is_primary_thread(cpu))
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continue;
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ret = cpu_down_maps_locked(cpu, CPUHP_OFFLINE);
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if (ret)
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break;
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/*
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* As this needs to hold the cpu maps lock it's impossible
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* to call device_offline() because that ends up calling
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* cpu_down() which takes cpu maps lock. cpu maps lock
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* needs to be held as this might race against in kernel
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* abusers of the hotplug machinery (thermal management).
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*
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* So nothing would update device:offline state. That would
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* leave the sysfs entry stale and prevent onlining after
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* smt control has been changed to 'off' again. This is
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* called under the sysfs hotplug lock, so it is properly
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* serialized against the regular offline usage.
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*/
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cpuhp_offline_cpu_device(cpu);
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}
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if (!ret)
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cpu_smt_control = ctrlval;
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cpu_maps_update_done();
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return ret;
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}
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int cpuhp_smt_enable(void)
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{
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int cpu, ret = 0;
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cpu_maps_update_begin();
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cpu_smt_control = CPU_SMT_ENABLED;
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for_each_present_cpu(cpu) {
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/* Skip online CPUs and CPUs on offline nodes */
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if (cpu_online(cpu) || !node_online(cpu_to_node(cpu)))
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continue;
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ret = _cpu_up(cpu, 0, CPUHP_ONLINE);
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if (ret)
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break;
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/* See comment in cpuhp_smt_disable() */
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cpuhp_online_cpu_device(cpu);
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}
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cpu_maps_update_done();
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return ret;
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}
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static ssize_t
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__store_smt_control(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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