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kernel/cpu.c
66.9 KB
1da177e4c Linux-2.6.12-rc2 |
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/* CPU control. * (C) 2001, 2002, 2003, 2004 Rusty Russell * * This code is licenced under the GPL. */ |
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#include <linux/sched/mm.h> |
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#include <linux/proc_fs.h> #include <linux/smp.h> #include <linux/init.h> #include <linux/notifier.h> |
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#include <linux/sched/signal.h> |
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#include <linux/sched/hotplug.h> |
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#include <linux/sched/isolation.h> |
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#include <linux/sched/task.h> |
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#include <linux/sched/smt.h> |
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#include <linux/unistd.h> #include <linux/cpu.h> |
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#include <linux/oom.h> #include <linux/rcupdate.h> |
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#include <linux/export.h> |
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#include <linux/bug.h> |
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#include <linux/kthread.h> #include <linux/stop_machine.h> |
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#include <linux/mutex.h> |
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#include <linux/gfp.h> |
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#include <linux/suspend.h> |
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#include <linux/lockdep.h> |
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#include <linux/tick.h> |
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#include <linux/irq.h> |
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#include <linux/nmi.h> |
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#include <linux/smpboot.h> |
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#include <linux/relay.h> |
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#include <linux/slab.h> |
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#include <linux/percpu-rwsem.h> |
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#include <uapi/linux/sched/types.h> |
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#include <linux/cpuset.h> |
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|
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#include <trace/events/power.h> |
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#define CREATE_TRACE_POINTS #include <trace/events/cpuhp.h> |
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|
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#undef CREATE_TRACE_POINTS #include <trace/hooks/sched.h> |
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#include "smpboot.h" |
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/** * cpuhp_cpu_state - Per cpu hotplug state storage * @state: The current cpu state * @target: The target state |
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* @thread: Pointer to the hotplug thread * @should_run: Thread should execute |
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* @rollback: Perform a rollback |
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* @single: Single callback invocation * @bringup: Single callback bringup or teardown selector * @cb_state: The state for a single callback (install/uninstall) |
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* @result: Result of the operation |
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* @done_up: Signal completion to the issuer of the task for cpu-up * @done_down: Signal completion to the issuer of the task for cpu-down |
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*/ struct cpuhp_cpu_state { enum cpuhp_state state; enum cpuhp_state target; |
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enum cpuhp_state fail; |
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#ifdef CONFIG_SMP struct task_struct *thread; bool should_run; |
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bool rollback; |
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bool single; bool bringup; |
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struct hlist_node *node; |
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struct hlist_node *last; |
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enum cpuhp_state cb_state; |
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int result; |
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struct completion done_up; struct completion done_down; |
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#endif |
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}; |
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static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state) = { .fail = CPUHP_INVALID, }; |
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|
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#ifdef CONFIG_SMP cpumask_t cpus_booted_once_mask; #endif |
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#if defined(CONFIG_LOCKDEP) && defined(CONFIG_SMP) |
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static struct lockdep_map cpuhp_state_up_map = STATIC_LOCKDEP_MAP_INIT("cpuhp_state-up", &cpuhp_state_up_map); static struct lockdep_map cpuhp_state_down_map = STATIC_LOCKDEP_MAP_INIT("cpuhp_state-down", &cpuhp_state_down_map); |
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static inline void cpuhp_lock_acquire(bool bringup) |
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{ lock_map_acquire(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map); } |
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static inline void cpuhp_lock_release(bool bringup) |
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{ lock_map_release(bringup ? &cpuhp_state_up_map : &cpuhp_state_down_map); } #else |
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static inline void cpuhp_lock_acquire(bool bringup) { } static inline void cpuhp_lock_release(bool bringup) { } |
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|
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#endif |
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/** * cpuhp_step - Hotplug state machine step * @name: Name of the step * @startup: Startup function of the step * @teardown: Teardown function of the step |
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* @cant_stop: Bringup/teardown can't be stopped at this step |
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*/ struct cpuhp_step { |
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const char *name; union { |
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int (*single)(unsigned int cpu); int (*multi)(unsigned int cpu, struct hlist_node *node); } startup; |
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union { |
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int (*single)(unsigned int cpu); int (*multi)(unsigned int cpu, struct hlist_node *node); } teardown; |
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struct hlist_head list; |
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bool cant_stop; bool multi_instance; |
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}; |
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static DEFINE_MUTEX(cpuhp_state_mutex); |
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static struct cpuhp_step cpuhp_hp_states[]; |
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|
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static struct cpuhp_step *cpuhp_get_step(enum cpuhp_state state) { |
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return cpuhp_hp_states + state; |
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} |
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/** * cpuhp_invoke_callback _ Invoke the callbacks for a given state * @cpu: The cpu for which the callback should be invoked |
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* @state: The state to do callbacks for |
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* @bringup: True if the bringup callback should be invoked |
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* @node: For multi-instance, do a single entry callback for install/remove * @lastp: For multi-instance rollback, remember how far we got |
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* |
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* Called from cpu hotplug and from the state register machinery. |
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*/ |
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static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state, |
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bool bringup, struct hlist_node *node, struct hlist_node **lastp) |
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{ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
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struct cpuhp_step *step = cpuhp_get_step(state); |
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int (*cbm)(unsigned int cpu, struct hlist_node *node); int (*cb)(unsigned int cpu); int ret, cnt; |
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if (st->fail == state) { st->fail = CPUHP_INVALID; if (!(bringup ? step->startup.single : step->teardown.single)) return 0; return -EAGAIN; } |
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if (!step->multi_instance) { |
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WARN_ON_ONCE(lastp && *lastp); |
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cb = bringup ? step->startup.single : step->teardown.single; |
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if (!cb) return 0; |
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trace_cpuhp_enter(cpu, st->target, state, cb); |
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ret = cb(cpu); |
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trace_cpuhp_exit(cpu, st->state, state, ret); |
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return ret; } |
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cbm = bringup ? step->startup.multi : step->teardown.multi; |
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if (!cbm) return 0; /* Single invocation for instance add/remove */ if (node) { |
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WARN_ON_ONCE(lastp && *lastp); |
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trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); ret = cbm(cpu, node); trace_cpuhp_exit(cpu, st->state, state, ret); return ret; } /* State transition. Invoke on all instances */ cnt = 0; hlist_for_each(node, &step->list) { |
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if (lastp && node == *lastp) break; |
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trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); ret = cbm(cpu, node); trace_cpuhp_exit(cpu, st->state, state, ret); |
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if (ret) { if (!lastp) goto err; *lastp = node; return ret; } |
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cnt++; } |
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if (lastp) *lastp = NULL; |
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return 0; err: /* Rollback the instances if one failed */ |
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cbm = !bringup ? step->startup.multi : step->teardown.multi; |
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if (!cbm) return ret; hlist_for_each(node, &step->list) { if (!cnt--) break; |
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trace_cpuhp_multi_enter(cpu, st->target, state, cbm, node); ret = cbm(cpu, node); trace_cpuhp_exit(cpu, st->state, state, ret); /* * Rollback must not fail, */ WARN_ON_ONCE(ret); |
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} return ret; } |
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#ifdef CONFIG_SMP |
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static bool cpuhp_is_ap_state(enum cpuhp_state state) { /* * The extra check for CPUHP_TEARDOWN_CPU is only for documentation * purposes as that state is handled explicitly in cpu_down. */ return state > CPUHP_BRINGUP_CPU && state != CPUHP_TEARDOWN_CPU; } |
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static inline void wait_for_ap_thread(struct cpuhp_cpu_state *st, bool bringup) { struct completion *done = bringup ? &st->done_up : &st->done_down; wait_for_completion(done); } static inline void complete_ap_thread(struct cpuhp_cpu_state *st, bool bringup) { struct completion *done = bringup ? &st->done_up : &st->done_down; complete(done); } /* * The former STARTING/DYING states, ran with IRQs disabled and must not fail. */ static bool cpuhp_is_atomic_state(enum cpuhp_state state) { return CPUHP_AP_IDLE_DEAD <= state && state < CPUHP_AP_ONLINE; } |
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/* Serializes the updates to cpu_online_mask, cpu_present_mask */ |
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static DEFINE_MUTEX(cpu_add_remove_lock); |
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bool cpuhp_tasks_frozen; EXPORT_SYMBOL_GPL(cpuhp_tasks_frozen); |
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|
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/* |
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* The following two APIs (cpu_maps_update_begin/done) must be used when * attempting to serialize the updates to cpu_online_mask & cpu_present_mask. |
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*/ void cpu_maps_update_begin(void) { mutex_lock(&cpu_add_remove_lock); } void cpu_maps_update_done(void) { mutex_unlock(&cpu_add_remove_lock); } |
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|
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/* * If set, cpu_up and cpu_down will return -EBUSY and do nothing. |
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* Should always be manipulated under cpu_add_remove_lock */ static int cpu_hotplug_disabled; |
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#ifdef CONFIG_HOTPLUG_CPU |
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DEFINE_STATIC_PERCPU_RWSEM(cpu_hotplug_lock); |
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|
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void cpus_read_lock(void) |
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{ |
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percpu_down_read(&cpu_hotplug_lock); |
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} |
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EXPORT_SYMBOL_GPL(cpus_read_lock); |
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|
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int cpus_read_trylock(void) { return percpu_down_read_trylock(&cpu_hotplug_lock); } EXPORT_SYMBOL_GPL(cpus_read_trylock); |
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void cpus_read_unlock(void) |
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{ |
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percpu_up_read(&cpu_hotplug_lock); |
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} |
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EXPORT_SYMBOL_GPL(cpus_read_unlock); |
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|
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void cpus_write_lock(void) |
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{ |
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percpu_down_write(&cpu_hotplug_lock); |
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} |
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|
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void cpus_write_unlock(void) |
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{ |
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percpu_up_write(&cpu_hotplug_lock); |
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} |
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void lockdep_assert_cpus_held(void) |
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{ |
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/* * We can't have hotplug operations before userspace starts running, * and some init codepaths will knowingly not take the hotplug lock. * This is all valid, so mute lockdep until it makes sense to report * unheld locks. */ if (system_state < SYSTEM_RUNNING) return; |
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percpu_rwsem_assert_held(&cpu_hotplug_lock); |
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} |
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|
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static void lockdep_acquire_cpus_lock(void) { |
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rwsem_acquire(&cpu_hotplug_lock.dep_map, 0, 0, _THIS_IP_); |
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} static void lockdep_release_cpus_lock(void) { |
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rwsem_release(&cpu_hotplug_lock.dep_map, _THIS_IP_); |
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} |
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/* * Wait for currently running CPU hotplug operations to complete (if any) and * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the * hotplug path before performing hotplug operations. So acquiring that lock * guarantees mutual exclusion from any currently running hotplug operations. */ void cpu_hotplug_disable(void) { cpu_maps_update_begin(); |
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cpu_hotplug_disabled++; |
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cpu_maps_update_done(); } |
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EXPORT_SYMBOL_GPL(cpu_hotplug_disable); |
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|
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static void __cpu_hotplug_enable(void) { if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable ")) return; cpu_hotplug_disabled--; } |
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void cpu_hotplug_enable(void) { cpu_maps_update_begin(); |
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__cpu_hotplug_enable(); |
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cpu_maps_update_done(); } |
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EXPORT_SYMBOL_GPL(cpu_hotplug_enable); |
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#else static void lockdep_acquire_cpus_lock(void) { } static void lockdep_release_cpus_lock(void) { } |
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#endif /* CONFIG_HOTPLUG_CPU */ |
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|
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/* * Architectures that need SMT-specific errata handling during SMT hotplug * should override this. */ void __weak arch_smt_update(void) { } |
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#ifdef CONFIG_HOTPLUG_SMT enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED; |
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|
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void __init cpu_smt_disable(bool force) |
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{ |
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if (!cpu_smt_possible()) |
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return; if (force) { |
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pr_info("SMT: Force disabled "); cpu_smt_control = CPU_SMT_FORCE_DISABLED; |
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} else { |
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pr_info("SMT: disabled "); |
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cpu_smt_control = CPU_SMT_DISABLED; |
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} |
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} |
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/* * The decision whether SMT is supported can only be done after the full |
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* CPU identification. Called from architecture code. |
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*/ void __init cpu_smt_check_topology(void) { |
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if (!topology_smt_supported()) |
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cpu_smt_control = CPU_SMT_NOT_SUPPORTED; } |
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static int __init smt_cmdline_disable(char *str) { cpu_smt_disable(str && !strcmp(str, "force")); |
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return 0; } early_param("nosmt", smt_cmdline_disable); static inline bool cpu_smt_allowed(unsigned int cpu) { |
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if (cpu_smt_control == CPU_SMT_ENABLED) |
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return true; |
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409 |
if (topology_is_primary_thread(cpu)) |
0cc3cd216 cpu/hotplug: Boot... |
410 411 412 413 414 |
return true; /* * On x86 it's required to boot all logical CPUs at least once so * that the init code can get a chance to set CR4.MCE on each |
182e073f6 cpu/hotplug: Fix ... |
415 |
* CPU. Otherwise, a broadcasted MCE observing CR4.MCE=0b on any |
0cc3cd216 cpu/hotplug: Boot... |
416 417 |
* core will shutdown the machine. */ |
e797bda3f smp/hotplug: Trac... |
418 |
return !cpumask_test_cpu(cpu, &cpus_booted_once_mask); |
0cc3cd216 cpu/hotplug: Boot... |
419 |
} |
e1572f1d0 cpu/SMT: create a... |
420 421 422 423 424 425 426 427 |
/* Returns true if SMT is not supported of forcefully (irreversibly) disabled */ bool cpu_smt_possible(void) { return cpu_smt_control != CPU_SMT_FORCE_DISABLED && cpu_smt_control != CPU_SMT_NOT_SUPPORTED; } EXPORT_SYMBOL_GPL(cpu_smt_possible); |
0cc3cd216 cpu/hotplug: Boot... |
428 429 430 |
#else static inline bool cpu_smt_allowed(unsigned int cpu) { return true; } #endif |
4dddfb5fa smp/hotplug: Rewr... |
431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 |
static inline enum cpuhp_state cpuhp_set_state(struct cpuhp_cpu_state *st, enum cpuhp_state target) { enum cpuhp_state prev_state = st->state; st->rollback = false; st->last = NULL; st->target = target; st->single = false; st->bringup = st->state < target; return prev_state; } static inline void cpuhp_reset_state(struct cpuhp_cpu_state *st, enum cpuhp_state prev_state) { st->rollback = true; /* * If we have st->last we need to undo partial multi_instance of this * state first. Otherwise start undo at the previous state. */ if (!st->last) { if (st->bringup) st->state--; else st->state++; } st->target = prev_state; st->bringup = !st->bringup; } /* Regular hotplug invocation of the AP hotplug thread */ static void __cpuhp_kick_ap(struct cpuhp_cpu_state *st) { if (!st->single && st->state == st->target) return; st->result = 0; /* * Make sure the above stores are visible before should_run becomes * true. Paired with the mb() above in cpuhp_thread_fun() */ smp_mb(); st->should_run = true; wake_up_process(st->thread); |
5ebe7742f smp/hotplug: Diff... |
480 |
wait_for_ap_thread(st, st->bringup); |
4dddfb5fa smp/hotplug: Rewr... |
481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 |
} static int cpuhp_kick_ap(struct cpuhp_cpu_state *st, enum cpuhp_state target) { enum cpuhp_state prev_state; int ret; prev_state = cpuhp_set_state(st, target); __cpuhp_kick_ap(st); if ((ret = st->result)) { cpuhp_reset_state(st, prev_state); __cpuhp_kick_ap(st); } return ret; } |
9cd4f1a4e smp/hotplug: Move... |
497 |
|
8df3e07e7 cpu/hotplug: Let ... |
498 499 500 |
static int bringup_wait_for_ap(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
9cd4f1a4e smp/hotplug: Move... |
501 |
/* Wait for the CPU to reach CPUHP_AP_ONLINE_IDLE */ |
5ebe7742f smp/hotplug: Diff... |
502 |
wait_for_ap_thread(st, true); |
dea1d0f5f smp/hotplug: Repl... |
503 504 |
if (WARN_ON_ONCE((!cpu_online(cpu)))) return -ECANCELED; |
9cd4f1a4e smp/hotplug: Move... |
505 |
|
45178ac0c cpu/hotplug, stop... |
506 |
/* Unpark the hotplug thread of the target cpu */ |
9cd4f1a4e smp/hotplug: Move... |
507 |
kthread_unpark(st->thread); |
0cc3cd216 cpu/hotplug: Boot... |
508 509 510 |
/* * SMT soft disabling on X86 requires to bring the CPU out of the * BIOS 'wait for SIPI' state in order to set the CR4.MCE bit. The |
f56020110 cpu/hotplug: Fix ... |
511 |
* CPU marked itself as booted_once in notify_cpu_starting() so the |
0cc3cd216 cpu/hotplug: Boot... |
512 513 514 515 516 |
* cpu_smt_allowed() check will now return false if this is not the * primary sibling. */ if (!cpu_smt_allowed(cpu)) return -ECANCELED; |
4dddfb5fa smp/hotplug: Rewr... |
517 518 519 520 |
if (st->target <= CPUHP_AP_ONLINE_IDLE) return 0; return cpuhp_kick_ap(st, st->target); |
8df3e07e7 cpu/hotplug: Let ... |
521 |
} |
ba9974624 cpu/hotplug: Rest... |
522 523 524 525 |
static int bringup_cpu(unsigned int cpu) { struct task_struct *idle = idle_thread_get(cpu); int ret; |
aa877175e cpu/hotplug: Prev... |
526 527 528 529 530 531 |
/* * Some architectures have to walk the irq descriptors to * setup the vector space for the cpu which comes online. * Prevent irq alloc/free across the bringup. */ irq_lock_sparse(); |
ba9974624 cpu/hotplug: Rest... |
532 533 |
/* Arch-specific enabling code. */ ret = __cpu_up(cpu, idle); |
aa877175e cpu/hotplug: Prev... |
534 |
irq_unlock_sparse(); |
530e9b76a cpu/hotplug: Remo... |
535 |
if (ret) |
ba9974624 cpu/hotplug: Rest... |
536 |
return ret; |
9cd4f1a4e smp/hotplug: Move... |
537 |
return bringup_wait_for_ap(cpu); |
ba9974624 cpu/hotplug: Rest... |
538 |
} |
bf2c59fce sched/core: Fix i... |
539 540 541 542 543 544 545 546 547 548 549 550 551 552 |
static int finish_cpu(unsigned int cpu) { struct task_struct *idle = idle_thread_get(cpu); struct mm_struct *mm = idle->active_mm; /* * idle_task_exit() will have switched to &init_mm, now * clean up any remaining active_mm state. */ if (mm != &init_mm) idle->active_mm = &init_mm; mmdrop(mm); return 0; } |
2e1a3483c cpu/hotplug: Spli... |
553 554 555 |
/* * Hotplug state machine related functions */ |
2e1a3483c cpu/hotplug: Spli... |
556 |
|
a724632ca cpu/hotplug: Rewo... |
557 |
static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) |
2e1a3483c cpu/hotplug: Spli... |
558 |
{ |
6fb86d972 cpu/hotplug: Remo... |
559 560 |
for (st->state--; st->state > st->target; st->state--) cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); |
2e1a3483c cpu/hotplug: Spli... |
561 |
} |
206b92353 cpu/hotplug: Prev... |
562 563 564 565 566 567 568 569 570 571 572 573 574 |
static inline bool can_rollback_cpu(struct cpuhp_cpu_state *st) { if (IS_ENABLED(CONFIG_HOTPLUG_CPU)) return true; /* * When CPU hotplug is disabled, then taking the CPU down is not * possible because takedown_cpu() and the architecture and * subsystem specific mechanisms are not available. So the CPU * which would be completely unplugged again needs to stay around * in the current state. */ return st->state <= CPUHP_BRINGUP_CPU; } |
2e1a3483c cpu/hotplug: Spli... |
575 |
static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, |
a724632ca cpu/hotplug: Rewo... |
576 |
enum cpuhp_state target) |
2e1a3483c cpu/hotplug: Spli... |
577 578 579 580 581 |
{ enum cpuhp_state prev_state = st->state; int ret = 0; while (st->state < target) { |
2e1a3483c cpu/hotplug: Spli... |
582 |
st->state++; |
96abb9685 smp/hotplug: Allo... |
583 |
ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); |
2e1a3483c cpu/hotplug: Spli... |
584 |
if (ret) { |
206b92353 cpu/hotplug: Prev... |
585 586 587 588 |
if (can_rollback_cpu(st)) { st->target = prev_state; undo_cpu_up(cpu, st); } |
2e1a3483c cpu/hotplug: Spli... |
589 590 591 592 593 |
break; } } return ret; } |
4cb28ced2 cpu/hotplug: Crea... |
594 595 596 597 598 599 |
/* * The cpu hotplug threads manage the bringup and teardown of the cpus */ static void cpuhp_create(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
5ebe7742f smp/hotplug: Diff... |
600 601 |
init_completion(&st->done_up); init_completion(&st->done_down); |
4cb28ced2 cpu/hotplug: Crea... |
602 603 604 605 606 607 608 609 |
} static int cpuhp_should_run(unsigned int cpu) { struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); return st->should_run; } |
4cb28ced2 cpu/hotplug: Crea... |
610 611 612 |
/* * Execute teardown/startup callbacks on the plugged cpu. Also used to invoke * callbacks when a state gets [un]installed at runtime. |
4dddfb5fa smp/hotplug: Rewr... |
613 614 615 616 617 618 619 620 621 622 |
* * Each invocation of this function by the smpboot thread does a single AP * state callback. * * It has 3 modes of operation: * - single: runs st->cb_state * - up: runs ++st->state, while st->state < st->target * - down: runs st->state--, while st->state > st->target * * When complete or on error, should_run is cleared and the completion is fired. |
4cb28ced2 cpu/hotplug: Crea... |
623 624 625 626 |
*/ static void cpuhp_thread_fun(unsigned int cpu) { struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
4dddfb5fa smp/hotplug: Rewr... |
627 628 |
bool bringup = st->bringup; enum cpuhp_state state; |
4cb28ced2 cpu/hotplug: Crea... |
629 |
|
f8b7530aa cpu/hotplug: Adju... |
630 631 |
if (WARN_ON_ONCE(!st->should_run)) return; |
4cb28ced2 cpu/hotplug: Crea... |
632 |
/* |
4dddfb5fa smp/hotplug: Rewr... |
633 634 |
* ACQUIRE for the cpuhp_should_run() load of ->should_run. Ensures * that if we see ->should_run we also see the rest of the state. |
4cb28ced2 cpu/hotplug: Crea... |
635 636 |
*/ smp_mb(); |
4cb28ced2 cpu/hotplug: Crea... |
637 |
|
cb92173d1 locking/lockdep, ... |
638 639 640 641 642 643 |
/* * The BP holds the hotplug lock, but we're now running on the AP, * ensure that anybody asserting the lock is held, will actually find * it so. */ lockdep_acquire_cpus_lock(); |
5f4b55e10 smp/hotplug: Diff... |
644 |
cpuhp_lock_acquire(bringup); |
4dddfb5fa smp/hotplug: Rewr... |
645 |
|
a724632ca cpu/hotplug: Rewo... |
646 |
if (st->single) { |
4dddfb5fa smp/hotplug: Rewr... |
647 648 649 650 651 652 653 654 |
state = st->cb_state; st->should_run = false; } else { if (bringup) { st->state++; state = st->state; st->should_run = (st->state < st->target); WARN_ON_ONCE(st->state > st->target); |
4cb28ced2 cpu/hotplug: Crea... |
655 |
} else { |
4dddfb5fa smp/hotplug: Rewr... |
656 657 658 659 |
state = st->state; st->state--; st->should_run = (st->state > st->target); WARN_ON_ONCE(st->state < st->target); |
4cb28ced2 cpu/hotplug: Crea... |
660 |
} |
4dddfb5fa smp/hotplug: Rewr... |
661 662 663 |
} WARN_ON_ONCE(!cpuhp_is_ap_state(state)); |
4dddfb5fa smp/hotplug: Rewr... |
664 665 666 667 |
if (cpuhp_is_atomic_state(state)) { local_irq_disable(); st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last); local_irq_enable(); |
3b9d6da67 cpu/hotplug: Fix ... |
668 |
|
4dddfb5fa smp/hotplug: Rewr... |
669 670 671 672 |
/* * STARTING/DYING must not fail! */ WARN_ON_ONCE(st->result); |
4cb28ced2 cpu/hotplug: Crea... |
673 |
} else { |
4dddfb5fa smp/hotplug: Rewr... |
674 675 676 677 678 679 680 681 682 683 684 |
st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last); } if (st->result) { /* * If we fail on a rollback, we're up a creek without no * paddle, no way forward, no way back. We loose, thanks for * playing. */ WARN_ON_ONCE(st->rollback); st->should_run = false; |
4cb28ced2 cpu/hotplug: Crea... |
685 |
} |
4dddfb5fa smp/hotplug: Rewr... |
686 |
|
5f4b55e10 smp/hotplug: Diff... |
687 |
cpuhp_lock_release(bringup); |
cb92173d1 locking/lockdep, ... |
688 |
lockdep_release_cpus_lock(); |
4dddfb5fa smp/hotplug: Rewr... |
689 690 |
if (!st->should_run) |
5ebe7742f smp/hotplug: Diff... |
691 |
complete_ap_thread(st, bringup); |
4cb28ced2 cpu/hotplug: Crea... |
692 693 694 |
} /* Invoke a single callback on a remote cpu */ |
a724632ca cpu/hotplug: Rewo... |
695 |
static int |
cf392d10b cpu/hotplug: Add ... |
696 697 |
cpuhp_invoke_ap_callback(int cpu, enum cpuhp_state state, bool bringup, struct hlist_node *node) |
4cb28ced2 cpu/hotplug: Crea... |
698 699 |
{ struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
4dddfb5fa smp/hotplug: Rewr... |
700 |
int ret; |
4cb28ced2 cpu/hotplug: Crea... |
701 702 703 |
if (!cpu_online(cpu)) return 0; |
5f4b55e10 smp/hotplug: Diff... |
704 705 706 707 708 |
cpuhp_lock_acquire(false); cpuhp_lock_release(false); cpuhp_lock_acquire(true); cpuhp_lock_release(true); |
49dfe2a67 cpuhotplug: Link ... |
709 |
|
6a4e24518 cpu/hotplug: Hand... |
710 711 712 713 714 |
/* * If we are up and running, use the hotplug thread. For early calls * we invoke the thread function directly. */ if (!st->thread) |
96abb9685 smp/hotplug: Allo... |
715 |
return cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
6a4e24518 cpu/hotplug: Hand... |
716 |
|
4dddfb5fa smp/hotplug: Rewr... |
717 718 719 720 721 |
st->rollback = false; st->last = NULL; st->node = node; st->bringup = bringup; |
4cb28ced2 cpu/hotplug: Crea... |
722 |
st->cb_state = state; |
a724632ca cpu/hotplug: Rewo... |
723 |
st->single = true; |
a724632ca cpu/hotplug: Rewo... |
724 |
|
4dddfb5fa smp/hotplug: Rewr... |
725 |
__cpuhp_kick_ap(st); |
4cb28ced2 cpu/hotplug: Crea... |
726 |
|
4cb28ced2 cpu/hotplug: Crea... |
727 |
/* |
4dddfb5fa smp/hotplug: Rewr... |
728 |
* If we failed and did a partial, do a rollback. |
4cb28ced2 cpu/hotplug: Crea... |
729 |
*/ |
4dddfb5fa smp/hotplug: Rewr... |
730 731 732 733 734 735 |
if ((ret = st->result) && st->last) { st->rollback = true; st->bringup = !bringup; __cpuhp_kick_ap(st); } |
1f7c70d6b cpu/hotplug: Rese... |
736 737 738 739 740 |
/* * Clean up the leftovers so the next hotplug operation wont use stale * data. */ st->node = st->last = NULL; |
4dddfb5fa smp/hotplug: Rewr... |
741 |
return ret; |
1cf4f629d cpu/hotplug: Move... |
742 743 744 745 746 |
} static int cpuhp_kick_ap_work(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
4dddfb5fa smp/hotplug: Rewr... |
747 748 |
enum cpuhp_state prev_state = st->state; int ret; |
1cf4f629d cpu/hotplug: Move... |
749 |
|
5f4b55e10 smp/hotplug: Diff... |
750 751 752 753 754 |
cpuhp_lock_acquire(false); cpuhp_lock_release(false); cpuhp_lock_acquire(true); cpuhp_lock_release(true); |
4dddfb5fa smp/hotplug: Rewr... |
755 756 757 758 759 760 |
trace_cpuhp_enter(cpu, st->target, prev_state, cpuhp_kick_ap_work); ret = cpuhp_kick_ap(st, st->target); trace_cpuhp_exit(cpu, st->state, prev_state, ret); return ret; |
4cb28ced2 cpu/hotplug: Crea... |
761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 |
} static struct smp_hotplug_thread cpuhp_threads = { .store = &cpuhp_state.thread, .create = &cpuhp_create, .thread_should_run = cpuhp_should_run, .thread_fn = cpuhp_thread_fun, .thread_comm = "cpuhp/%u", .selfparking = true, }; void __init cpuhp_threads_init(void) { BUG_ON(smpboot_register_percpu_thread(&cpuhp_threads)); kthread_unpark(this_cpu_read(cpuhp_state.thread)); } |
777c6e0da hotplug: Make reg... |
777 |
#ifdef CONFIG_HOTPLUG_CPU |
8ff00399b kernel/cpu: add a... |
778 779 780 |
#ifndef arch_clear_mm_cpumask_cpu #define arch_clear_mm_cpumask_cpu(cpu, mm) cpumask_clear_cpu(cpu, mm_cpumask(mm)) #endif |
e4cc2f873 kernel/cpu.c: doc... |
781 782 783 784 785 786 787 788 789 790 791 792 |
/** * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU * @cpu: a CPU id * * This function walks all processes, finds a valid mm struct for each one and * then clears a corresponding bit in mm's cpumask. While this all sounds * trivial, there are various non-obvious corner cases, which this function * tries to solve in a safe manner. * * Also note that the function uses a somewhat relaxed locking scheme, so it may * be called only for an already offlined CPU. */ |
cb79295e2 cpu: introduce cl... |
793 794 795 796 797 798 799 800 801 802 803 |
void clear_tasks_mm_cpumask(int cpu) { struct task_struct *p; /* * This function is called after the cpu is taken down and marked * offline, so its not like new tasks will ever get this cpu set in * their mm mask. -- Peter Zijlstra * Thus, we may use rcu_read_lock() here, instead of grabbing * full-fledged tasklist_lock. */ |
e4cc2f873 kernel/cpu.c: doc... |
804 |
WARN_ON(cpu_online(cpu)); |
cb79295e2 cpu: introduce cl... |
805 806 807 |
rcu_read_lock(); for_each_process(p) { struct task_struct *t; |
e4cc2f873 kernel/cpu.c: doc... |
808 809 810 811 |
/* * Main thread might exit, but other threads may still have * a valid mm. Find one. */ |
cb79295e2 cpu: introduce cl... |
812 813 814 |
t = find_lock_task_mm(p); if (!t) continue; |
8ff00399b kernel/cpu: add a... |
815 |
arch_clear_mm_cpumask_cpu(cpu, t->mm); |
cb79295e2 cpu: introduce cl... |
816 817 818 819 |
task_unlock(t); } rcu_read_unlock(); } |
1da177e4c Linux-2.6.12-rc2 |
820 |
/* Take this CPU down. */ |
71cf5aeeb kernel, cpu: Remo... |
821 |
static int take_cpu_down(void *_param) |
1da177e4c Linux-2.6.12-rc2 |
822 |
{ |
4baa0afc6 cpu/hotplug: Conv... |
823 824 |
struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); enum cpuhp_state target = max((int)st->target, CPUHP_AP_OFFLINE); |
090e77c39 cpu/hotplug: Rest... |
825 |
int err, cpu = smp_processor_id(); |
724a86881 smp/hotplug: Call... |
826 |
int ret; |
1da177e4c Linux-2.6.12-rc2 |
827 |
|
1da177e4c Linux-2.6.12-rc2 |
828 829 830 |
/* Ensure this CPU doesn't handle any more interrupts. */ err = __cpu_disable(); if (err < 0) |
f37051364 [PATCH] i386 CPU ... |
831 |
return err; |
1da177e4c Linux-2.6.12-rc2 |
832 |
|
a724632ca cpu/hotplug: Rewo... |
833 834 835 836 837 838 |
/* * We get here while we are in CPUHP_TEARDOWN_CPU state and we must not * do this step again. */ WARN_ON(st->state != CPUHP_TEARDOWN_CPU); st->state--; |
4baa0afc6 cpu/hotplug: Conv... |
839 |
/* Invoke the former CPU_DYING callbacks */ |
724a86881 smp/hotplug: Call... |
840 841 842 843 844 845 846 |
for (; st->state > target; st->state--) { ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); /* * DYING must not fail! */ WARN_ON_ONCE(ret); } |
4baa0afc6 cpu/hotplug: Conv... |
847 |
|
52c063d1a clockevents: Make... |
848 849 |
/* Give up timekeeping duties */ tick_handover_do_timer(); |
1b72d4323 tick: Remove outg... |
850 851 |
/* Remove CPU from timer broadcasting */ tick_offline_cpu(cpu); |
14e568e78 stop_machine: Use... |
852 |
/* Park the stopper thread */ |
090e77c39 cpu/hotplug: Rest... |
853 |
stop_machine_park(cpu); |
f37051364 [PATCH] i386 CPU ... |
854 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
855 |
} |
984581728 cpu/hotplug: Spli... |
856 |
static int takedown_cpu(unsigned int cpu) |
1da177e4c Linux-2.6.12-rc2 |
857 |
{ |
e69aab131 cpu/hotplug: Make... |
858 |
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
984581728 cpu/hotplug: Spli... |
859 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
860 |
|
2a58c527b cpu/hotplug: Fix ... |
861 |
/* Park the smpboot threads */ |
1cf4f629d cpu/hotplug: Move... |
862 |
kthread_park(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
6acce3ef8 sched: Remove get... |
863 |
/* |
a89941816 hotplug: Prevent ... |
864 865 |
* Prevent irq alloc/free while the dying cpu reorganizes the * interrupt affinities. |
6acce3ef8 sched: Remove get... |
866 |
*/ |
a89941816 hotplug: Prevent ... |
867 |
irq_lock_sparse(); |
6acce3ef8 sched: Remove get... |
868 |
|
a89941816 hotplug: Prevent ... |
869 870 871 |
/* * So now all preempt/rcu users must observe !cpu_active(). */ |
210e21331 cpu/hotplug: Use ... |
872 |
err = stop_machine_cpuslocked(take_cpu_down, NULL, cpumask_of(cpu)); |
043215875 Hotplug CPU: don'... |
873 |
if (err) { |
3b9d6da67 cpu/hotplug: Fix ... |
874 |
/* CPU refused to die */ |
a89941816 hotplug: Prevent ... |
875 |
irq_unlock_sparse(); |
3b9d6da67 cpu/hotplug: Fix ... |
876 877 |
/* Unpark the hotplug thread so we can rollback there */ kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); |
984581728 cpu/hotplug: Spli... |
878 |
return err; |
8fa1d7d3b [PATCH] cpu-hotpl... |
879 |
} |
043215875 Hotplug CPU: don'... |
880 |
BUG_ON(cpu_online(cpu)); |
1da177e4c Linux-2.6.12-rc2 |
881 |
|
48c5ccae8 sched: Simplify c... |
882 |
/* |
5b1ead680 cpu/hotplug: Fix ... |
883 884 |
* The teardown callback for CPUHP_AP_SCHED_STARTING will have removed * all runnable tasks from the CPU, there's only the idle task left now |
48c5ccae8 sched: Simplify c... |
885 |
* that the migration thread is done doing the stop_machine thing. |
51a96c778 cpu: Remove incor... |
886 887 |
* * Wait for the stop thread to go away. |
48c5ccae8 sched: Simplify c... |
888 |
*/ |
5ebe7742f smp/hotplug: Diff... |
889 |
wait_for_ap_thread(st, false); |
e69aab131 cpu/hotplug: Make... |
890 |
BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); |
1da177e4c Linux-2.6.12-rc2 |
891 |
|
a89941816 hotplug: Prevent ... |
892 893 |
/* Interrupts are moved away from the dying cpu, reenable alloc/free */ irq_unlock_sparse(); |
345527b1e clockevents: Fix ... |
894 |
hotplug_cpu__broadcast_tick_pull(cpu); |
1da177e4c Linux-2.6.12-rc2 |
895 896 |
/* This actually kills the CPU. */ __cpu_die(cpu); |
a49b116dc clockevents: Clea... |
897 |
tick_cleanup_dead_cpu(cpu); |
a58163d8c rcu: Migrate call... |
898 |
rcutree_migrate_callbacks(cpu); |
984581728 cpu/hotplug: Spli... |
899 900 |
return 0; } |
1da177e4c Linux-2.6.12-rc2 |
901 |
|
71f87b2fc cpu/hotplug: Plug... |
902 903 904 |
static void cpuhp_complete_idle_dead(void *arg) { struct cpuhp_cpu_state *st = arg; |
5ebe7742f smp/hotplug: Diff... |
905 |
complete_ap_thread(st, false); |
71f87b2fc cpu/hotplug: Plug... |
906 |
} |
e69aab131 cpu/hotplug: Make... |
907 908 909 910 911 |
void cpuhp_report_idle_dead(void) { struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); BUG_ON(st->state != CPUHP_AP_OFFLINE); |
27d50c7ee rcu: Make CPU_DYI... |
912 |
rcu_report_dead(smp_processor_id()); |
71f87b2fc cpu/hotplug: Plug... |
913 914 915 916 917 918 919 |
st->state = CPUHP_AP_IDLE_DEAD; /* * We cannot call complete after rcu_report_dead() so we delegate it * to an online cpu. */ smp_call_function_single(cpumask_first(cpu_online_mask), cpuhp_complete_idle_dead, st, 0); |
e69aab131 cpu/hotplug: Make... |
920 |
} |
4dddfb5fa smp/hotplug: Rewr... |
921 922 |
static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) { |
6fb86d972 cpu/hotplug: Remo... |
923 924 |
for (st->state++; st->state < st->target; st->state++) cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); |
4dddfb5fa smp/hotplug: Rewr... |
925 926 927 928 929 930 931 932 933 934 935 936 |
} static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, enum cpuhp_state target) { enum cpuhp_state prev_state = st->state; int ret = 0; for (; st->state > target; st->state--) { ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); if (ret) { st->target = prev_state; |
69fa6eb7d cpu/hotplug: Prev... |
937 938 |
if (st->state < prev_state) undo_cpu_down(cpu, st); |
4dddfb5fa smp/hotplug: Rewr... |
939 940 941 942 943 |
break; } } return ret; } |
cff7d378d cpu/hotplug: Conv... |
944 |
|
984581728 cpu/hotplug: Spli... |
945 |
/* Requires cpu_add_remove_lock to be held */ |
af1f40457 cpu/hotplug: Hand... |
946 947 |
static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
984581728 cpu/hotplug: Spli... |
948 |
{ |
cff7d378d cpu/hotplug: Conv... |
949 950 |
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int prev_state, ret = 0; |
984581728 cpu/hotplug: Spli... |
951 |
|
1734af629 ANDROID: cpu/hotp... |
952 |
if (num_active_cpus() == 1) |
984581728 cpu/hotplug: Spli... |
953 |
return -EBUSY; |
757c989b9 cpu/hotplug: Make... |
954 |
if (!cpu_present(cpu)) |
984581728 cpu/hotplug: Spli... |
955 |
return -EINVAL; |
8f553c498 cpu/hotplug: Prov... |
956 |
cpus_write_lock(); |
984581728 cpu/hotplug: Spli... |
957 958 |
cpuhp_tasks_frozen = tasks_frozen; |
4dddfb5fa smp/hotplug: Rewr... |
959 |
prev_state = cpuhp_set_state(st, target); |
1cf4f629d cpu/hotplug: Move... |
960 961 962 963 |
/* * If the current CPU state is in the range of the AP hotplug thread, * then we need to kick the thread. */ |
8df3e07e7 cpu/hotplug: Let ... |
964 |
if (st->state > CPUHP_TEARDOWN_CPU) { |
4dddfb5fa smp/hotplug: Rewr... |
965 |
st->target = max((int)target, CPUHP_TEARDOWN_CPU); |
1cf4f629d cpu/hotplug: Move... |
966 967 968 969 970 971 972 973 974 975 976 977 |
ret = cpuhp_kick_ap_work(cpu); /* * The AP side has done the error rollback already. Just * return the error code.. */ if (ret) goto out; /* * We might have stopped still in the range of the AP hotplug * thread. Nothing to do anymore. */ |
8df3e07e7 cpu/hotplug: Let ... |
978 |
if (st->state > CPUHP_TEARDOWN_CPU) |
1cf4f629d cpu/hotplug: Move... |
979 |
goto out; |
4dddfb5fa smp/hotplug: Rewr... |
980 981 |
st->target = target; |
1cf4f629d cpu/hotplug: Move... |
982 983 |
} /* |
8df3e07e7 cpu/hotplug: Let ... |
984 |
* The AP brought itself down to CPUHP_TEARDOWN_CPU. So we need |
1cf4f629d cpu/hotplug: Move... |
985 986 |
* to do the further cleanups. */ |
a724632ca cpu/hotplug: Rewo... |
987 |
ret = cpuhp_down_callbacks(cpu, st, target); |
69fa6eb7d cpu/hotplug: Prev... |
988 |
if (ret && st->state == CPUHP_TEARDOWN_CPU && st->state < prev_state) { |
4dddfb5fa smp/hotplug: Rewr... |
989 990 |
cpuhp_reset_state(st, prev_state); __cpuhp_kick_ap(st); |
3b9d6da67 cpu/hotplug: Fix ... |
991 |
} |
984581728 cpu/hotplug: Spli... |
992 |
|
1cf4f629d cpu/hotplug: Move... |
993 |
out: |
8f553c498 cpu/hotplug: Prov... |
994 |
cpus_write_unlock(); |
941154bd6 watchdog/hardlock... |
995 996 997 998 999 |
/* * Do post unplug cleanup. This is still protected against * concurrent CPU hotplug via cpu_add_remove_lock. */ lockup_detector_cleanup(); |
a74cfffb0 x86/speculation: ... |
1000 |
arch_smt_update(); |
cff7d378d cpu/hotplug: Conv... |
1001 |
return ret; |
e3920fb42 [PATCH] Disable C... |
1002 |
} |
cc1fe215e cpu/hotplug: Spli... |
1003 1004 1005 1006 1007 1008 |
static int cpu_down_maps_locked(unsigned int cpu, enum cpuhp_state target) { if (cpu_hotplug_disabled) return -EBUSY; return _cpu_down(cpu, 0, target); } |
33c3736ec cpu/hotplug: Hide... |
1009 |
static int cpu_down(unsigned int cpu, enum cpuhp_state target) |
e3920fb42 [PATCH] Disable C... |
1010 |
{ |
9ea09af3b stop_machine: int... |
1011 |
int err; |
e3920fb42 [PATCH] Disable C... |
1012 |
|
d221938c0 cpu-hotplug: refc... |
1013 |
cpu_maps_update_begin(); |
cc1fe215e cpu/hotplug: Spli... |
1014 |
err = cpu_down_maps_locked(cpu, target); |
d221938c0 cpu-hotplug: refc... |
1015 |
cpu_maps_update_done(); |
1da177e4c Linux-2.6.12-rc2 |
1016 1017 |
return err; } |
4dddfb5fa smp/hotplug: Rewr... |
1018 |
|
33c3736ec cpu/hotplug: Hide... |
1019 1020 1021 1022 1023 1024 1025 1026 1027 |
/** * cpu_device_down - Bring down a cpu device * @dev: Pointer to the cpu device to offline * * This function is meant to be used by device core cpu subsystem only. * * Other subsystems should use remove_cpu() instead. */ int cpu_device_down(struct device *dev) |
af1f40457 cpu/hotplug: Hand... |
1028 |
{ |
33c3736ec cpu/hotplug: Hide... |
1029 |
return cpu_down(dev->id, CPUHP_OFFLINE); |
af1f40457 cpu/hotplug: Hand... |
1030 |
} |
4dddfb5fa smp/hotplug: Rewr... |
1031 |
|
93ef1429e cpu/hotplug: Add ... |
1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 |
int remove_cpu(unsigned int cpu) { int ret; lock_device_hotplug(); ret = device_offline(get_cpu_device(cpu)); unlock_device_hotplug(); return ret; } EXPORT_SYMBOL_GPL(remove_cpu); |
683010f55 ANDROID: cpu/hotp... |
1043 |
extern bool dl_cpu_busy(unsigned int cpu); |
e19b8ce90 ANDROID: cpu/hotp... |
1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 |
int __pause_drain_rq(struct cpumask *cpus) { unsigned int cpu; int err = 0; /* * Disabling preemption avoids that one of the stopper, started from * sched_cpu_drain_rq(), blocks firing draining for the whole cpumask. */ preempt_disable(); for_each_cpu(cpu, cpus) { err = sched_cpu_drain_rq(cpu); if (err) break; } preempt_enable(); return err; } void __wait_drain_rq(struct cpumask *cpus) { unsigned int cpu; for_each_cpu(cpu, cpus) sched_cpu_drain_rq_wait(cpu); } |
683010f55 ANDROID: cpu/hotp... |
1071 1072 1073 1074 |
int pause_cpus(struct cpumask *cpus) { int err = 0; int cpu; |
614afa949 ANDROID: cpuhp/pa... |
1075 1076 1077 |
u64 start_time = 0; start_time = sched_clock(); |
683010f55 ANDROID: cpu/hotp... |
1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 |
cpu_maps_update_begin(); if (cpu_hotplug_disabled) { err = -EBUSY; goto err_cpu_maps_update; } /* Pausing an already inactive CPU isn't an error */ cpumask_and(cpus, cpus, cpu_active_mask); for_each_cpu(cpu, cpus) { if (!cpu_online(cpu) || dl_cpu_busy(cpu)) { err = -EBUSY; goto err_cpu_maps_update; } } if (cpumask_weight(cpus) >= num_active_cpus()) { err = -EBUSY; goto err_cpu_maps_update; } if (cpumask_empty(cpus)) goto err_cpu_maps_update; |
e19b8ce90 ANDROID: cpu/hotp... |
1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 |
/* * Lazy migration: * * We do care about how fast a CPU can go idle and stay this in this * state. If we try to take the cpus_write_lock() here, we would have * to wait for a few dozens of ms, as this function might schedule. * However, we can, as a first step, flip the active mask and migrate * anything currently on the run-queue, to give a chance to the paused * CPUs to reach quickly an idle state. There's a risk meanwhile for * another CPU to observe an out-of-date active_mask or to incompletely * update a cpuset. Both problems would be resolved later in the slow * path, which ensures active_mask synchronization, triggers a cpuset * rebuild and migrate any task that would have escaped the lazy * migration. */ for_each_cpu(cpu, cpus) set_cpu_active(cpu, false); err = __pause_drain_rq(cpus); if (err) { __wait_drain_rq(cpus); for_each_cpu(cpu, cpus) set_cpu_active(cpu, true); goto err_cpu_maps_update; } /* * Slow path deactivation: * * Now that paused CPUs are most likely idle, we can go through a * complete scheduler deactivation. * * The cpu_active_mask being already set and cpus_write_lock calling * synchronize_rcu(), we know that all preempt-disabled and RCU users * will observe the updated value. */ |
683010f55 ANDROID: cpu/hotp... |
1138 |
cpus_write_lock(); |
e19b8ce90 ANDROID: cpu/hotp... |
1139 |
__wait_drain_rq(cpus); |
683010f55 ANDROID: cpu/hotp... |
1140 1141 1142 1143 1144 1145 |
cpuhp_tasks_frozen = 0; if (sched_cpus_deactivate_nosync(cpus)) { err = -EBUSY; goto err_cpus_write_unlock; } |
e19b8ce90 ANDROID: cpu/hotp... |
1146 1147 1148 1149 1150 1151 1152 |
err = __pause_drain_rq(cpus); __wait_drain_rq(cpus); if (err) { for_each_cpu(cpu, cpus) sched_cpu_activate(cpu); goto err_cpus_write_unlock; } |
683010f55 ANDROID: cpu/hotp... |
1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 |
/* * Even if living on the side of the regular HP path, pause is using * one of the HP step (CPUHP_AP_ACTIVE). This should be reflected on the * current state of the CPU. */ for_each_cpu(cpu, cpus) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); st->state = CPUHP_AP_ACTIVE - 1; st->target = st->state; } err_cpus_write_unlock: cpus_write_unlock(); err_cpu_maps_update: cpu_maps_update_done(); |
614afa949 ANDROID: cpuhp/pa... |
1169 |
trace_cpuhp_pause(cpus, start_time, 1); |
683010f55 ANDROID: cpu/hotp... |
1170 1171 1172 1173 1174 1175 1176 1177 |
return err; } EXPORT_SYMBOL_GPL(pause_cpus); int resume_cpus(struct cpumask *cpus) { unsigned int cpu; int err = 0; |
614afa949 ANDROID: cpuhp/pa... |
1178 1179 1180 |
u64 start_time = 0; start_time = sched_clock(); |
683010f55 ANDROID: cpu/hotp... |
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 |
cpu_maps_update_begin(); if (cpu_hotplug_disabled) { err = -EBUSY; goto err_cpu_maps_update; } /* Resuming an already active CPU isn't an error */ cpumask_andnot(cpus, cpus, cpu_active_mask); for_each_cpu(cpu, cpus) { if (!cpu_online(cpu)) { err = -EBUSY; goto err_cpu_maps_update; } } if (cpumask_empty(cpus)) goto err_cpu_maps_update; |
1d3a64fbd ANDROID: cpu/hotp... |
1201 1202 |
for_each_cpu(cpu, cpus) set_cpu_active(cpu, true); |
782131fed ANDROID: cpu/hotp... |
1203 1204 1205 |
trace_android_rvh_resume_cpus(cpus, &err); if (err) goto err_cpu_maps_update; |
1d3a64fbd ANDROID: cpu/hotp... |
1206 1207 1208 1209 1210 |
/* Lazy Resume. Build domains immediately instead of scheduling * a workqueue. This is so that the cpu can pull load when * sent a load balancing kick. */ cpuset_hotplug_workfn(NULL); |
683010f55 ANDROID: cpu/hotp... |
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 |
cpus_write_lock(); cpuhp_tasks_frozen = 0; if (sched_cpus_activate(cpus)) { err = -EBUSY; goto err_cpus_write_unlock; } /* * see pause_cpus. */ for_each_cpu(cpu, cpus) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); st->state = CPUHP_ONLINE; st->target = st->state; } err_cpus_write_unlock: cpus_write_unlock(); err_cpu_maps_update: cpu_maps_update_done(); |
614afa949 ANDROID: cpuhp/pa... |
1234 |
trace_cpuhp_pause(cpus, start_time, 0); |
683010f55 ANDROID: cpu/hotp... |
1235 1236 1237 |
return err; } EXPORT_SYMBOL_GPL(resume_cpus); |
0441a5597 cpu/hotplug: Crea... |
1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 |
void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { unsigned int cpu; int error; cpu_maps_update_begin(); /* * Make certain the cpu I'm about to reboot on is online. * * This is inline to what migrate_to_reboot_cpu() already do. */ if (!cpu_online(primary_cpu)) primary_cpu = cpumask_first(cpu_online_mask); for_each_online_cpu(cpu) { if (cpu == primary_cpu) continue; error = cpu_down_maps_locked(cpu, CPUHP_OFFLINE); if (error) { pr_err("Failed to offline CPU%d - error=%d", cpu, error); break; } } /* * Ensure all but the reboot CPU are offline. */ BUG_ON(num_online_cpus() > 1); /* * Make sure the CPUs won't be enabled by someone else after this * point. Kexec will reboot to a new kernel shortly resetting * everything along the way. */ cpu_hotplug_disabled++; cpu_maps_update_done(); |
af1f40457 cpu/hotplug: Hand... |
1278 |
} |
4dddfb5fa smp/hotplug: Rewr... |
1279 1280 1281 |
#else #define takedown_cpu NULL |
1da177e4c Linux-2.6.12-rc2 |
1282 |
#endif /*CONFIG_HOTPLUG_CPU*/ |
4baa0afc6 cpu/hotplug: Conv... |
1283 |
/** |
ee1e714b9 cpu/hotplug: Remo... |
1284 |
* notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU |
4baa0afc6 cpu/hotplug: Conv... |
1285 1286 |
* @cpu: cpu that just started * |
4baa0afc6 cpu/hotplug: Conv... |
1287 1288 1289 1290 1291 1292 1293 |
* It must be called by the arch code on the new cpu, before the new cpu * enables interrupts and before the "boot" cpu returns from __cpu_up(). */ void notify_cpu_starting(unsigned int cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); enum cpuhp_state target = min((int)st->target, CPUHP_AP_ONLINE); |
724a86881 smp/hotplug: Call... |
1294 |
int ret; |
4baa0afc6 cpu/hotplug: Conv... |
1295 |
|
0c6d4576c cpu/hotplug: Get ... |
1296 |
rcu_cpu_starting(cpu); /* Enables RCU usage on this CPU. */ |
e797bda3f smp/hotplug: Trac... |
1297 |
cpumask_set_cpu(cpu, &cpus_booted_once_mask); |
4baa0afc6 cpu/hotplug: Conv... |
1298 |
while (st->state < target) { |
4baa0afc6 cpu/hotplug: Conv... |
1299 |
st->state++; |
724a86881 smp/hotplug: Call... |
1300 1301 1302 1303 1304 |
ret = cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); /* * STARTING must not fail! */ WARN_ON_ONCE(ret); |
4baa0afc6 cpu/hotplug: Conv... |
1305 1306 |
} } |
949338e35 cpu/hotplug: Move... |
1307 |
/* |
9cd4f1a4e smp/hotplug: Move... |
1308 |
* Called from the idle task. Wake up the controlling task which brings the |
45178ac0c cpu/hotplug, stop... |
1309 1310 |
* hotplug thread of the upcoming CPU up and then delegates the rest of the * online bringup to the hotplug thread. |
949338e35 cpu/hotplug: Move... |
1311 |
*/ |
8df3e07e7 cpu/hotplug: Let ... |
1312 |
void cpuhp_online_idle(enum cpuhp_state state) |
949338e35 cpu/hotplug: Move... |
1313 |
{ |
8df3e07e7 cpu/hotplug: Let ... |
1314 |
struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); |
8df3e07e7 cpu/hotplug: Let ... |
1315 1316 1317 1318 |
/* Happens for the boot cpu */ if (state != CPUHP_AP_ONLINE_IDLE) return; |
45178ac0c cpu/hotplug, stop... |
1319 1320 1321 1322 1323 |
/* * Unpart the stopper thread before we start the idle loop (and start * scheduling); this ensures the stopper task is always available. */ stop_machine_unpark(smp_processor_id()); |
8df3e07e7 cpu/hotplug: Let ... |
1324 |
st->state = CPUHP_AP_ONLINE_IDLE; |
5ebe7742f smp/hotplug: Diff... |
1325 |
complete_ap_thread(st, true); |
949338e35 cpu/hotplug: Move... |
1326 |
} |
c6e5f9d7c ANDROID: cpu-hotp... |
1327 1328 1329 1330 1331 1332 1333 1334 |
static int switch_to_rt_policy(void) { struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; unsigned int policy = current->policy; if (policy == SCHED_NORMAL) /* Switch to SCHED_FIFO from SCHED_NORMAL. */ return sched_setscheduler_nocheck(current, SCHED_FIFO, ¶m); |
c6e5f9d7c ANDROID: cpu-hotp... |
1335 |
else |
9da1f3710 ANDROID: cpu: Don... |
1336 |
return 1; |
c6e5f9d7c ANDROID: cpu-hotp... |
1337 1338 1339 1340 1341 1342 1343 1344 |
} static int switch_to_fair_policy(void) { struct sched_param param = { .sched_priority = 0 }; return sched_setscheduler_nocheck(current, SCHED_NORMAL, ¶m); } |
e3920fb42 [PATCH] Disable C... |
1345 |
/* Requires cpu_add_remove_lock to be held */ |
af1f40457 cpu/hotplug: Hand... |
1346 |
static int _cpu_up(unsigned int cpu, int tasks_frozen, enum cpuhp_state target) |
1da177e4c Linux-2.6.12-rc2 |
1347 |
{ |
cff7d378d cpu/hotplug: Conv... |
1348 |
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); |
3bb5d2ee3 smp, idle: Alloca... |
1349 |
struct task_struct *idle; |
2e1a3483c cpu/hotplug: Spli... |
1350 |
int ret = 0; |
1da177e4c Linux-2.6.12-rc2 |
1351 |
|
8f553c498 cpu/hotplug: Prov... |
1352 |
cpus_write_lock(); |
38498a67a smp: Add generic ... |
1353 |
|
757c989b9 cpu/hotplug: Make... |
1354 |
if (!cpu_present(cpu)) { |
5e5041f35 ACPI / processor:... |
1355 1356 1357 |
ret = -EINVAL; goto out; } |
757c989b9 cpu/hotplug: Make... |
1358 |
/* |
33c3736ec cpu/hotplug: Hide... |
1359 1360 |
* The caller of cpu_up() might have raced with another * caller. Nothing to do. |
757c989b9 cpu/hotplug: Make... |
1361 1362 |
*/ if (st->state >= target) |
38498a67a smp: Add generic ... |
1363 |
goto out; |
757c989b9 cpu/hotplug: Make... |
1364 1365 1366 1367 1368 1369 1370 1371 |
if (st->state == CPUHP_OFFLINE) { /* Let it fail before we try to bring the cpu up */ idle = idle_thread_get(cpu); if (IS_ERR(idle)) { ret = PTR_ERR(idle); goto out; } |
3bb5d2ee3 smp, idle: Alloca... |
1372 |
} |
38498a67a smp: Add generic ... |
1373 |
|
ba9974624 cpu/hotplug: Rest... |
1374 |
cpuhp_tasks_frozen = tasks_frozen; |
4dddfb5fa smp/hotplug: Rewr... |
1375 |
cpuhp_set_state(st, target); |
1cf4f629d cpu/hotplug: Move... |
1376 1377 1378 1379 |
/* * If the current CPU state is in the range of the AP hotplug thread, * then we need to kick the thread once more. */ |
8df3e07e7 cpu/hotplug: Let ... |
1380 |
if (st->state > CPUHP_BRINGUP_CPU) { |
1cf4f629d cpu/hotplug: Move... |
1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 |
ret = cpuhp_kick_ap_work(cpu); /* * The AP side has done the error rollback already. Just * return the error code.. */ if (ret) goto out; } /* * Try to reach the target state. We max out on the BP at |
8df3e07e7 cpu/hotplug: Let ... |
1392 |
* CPUHP_BRINGUP_CPU. After that the AP hotplug thread is |
1cf4f629d cpu/hotplug: Move... |
1393 1394 |
* responsible for bringing it up to the target state. */ |
8df3e07e7 cpu/hotplug: Let ... |
1395 |
target = min((int)target, CPUHP_BRINGUP_CPU); |
a724632ca cpu/hotplug: Rewo... |
1396 |
ret = cpuhp_up_callbacks(cpu, st, target); |
38498a67a smp: Add generic ... |
1397 |
out: |
8f553c498 cpu/hotplug: Prov... |
1398 |
cpus_write_unlock(); |
a74cfffb0 x86/speculation: ... |
1399 |
arch_smt_update(); |
e3920fb42 [PATCH] Disable C... |
1400 1401 |
return ret; } |
33c3736ec cpu/hotplug: Hide... |
1402 |
static int cpu_up(unsigned int cpu, enum cpuhp_state target) |
e3920fb42 [PATCH] Disable C... |
1403 1404 |
{ int err = 0; |
c6e5f9d7c ANDROID: cpu-hotp... |
1405 |
int switch_err; |
cf23422b9 cpu/mem hotplug: ... |
1406 |
|
e0b582ec5 cpumask: convert ... |
1407 |
if (!cpu_possible(cpu)) { |
84117da5b kernel/cpu.c: con... |
1408 1409 1410 |
pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time ", cpu); |
87d5e0236 kernel/cpu.c: del... |
1411 |
#if defined(CONFIG_IA64) |
84117da5b kernel/cpu.c: con... |
1412 1413 |
pr_err("please check additional_cpus= boot parameter "); |
73e753a50 CPU HOTPLUG: avoi... |
1414 1415 1416 |
#endif return -EINVAL; } |
e3920fb42 [PATCH] Disable C... |
1417 |
|
c6e5f9d7c ANDROID: cpu-hotp... |
1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 |
/* * CPU hotplug operations consists of many steps and each step * calls a callback of core kernel subsystem. CPU hotplug-in * operation may get preempted by other CFS tasks and whole * operation of cpu hotplug in CPU gets delayed. Switch the * current task to SCHED_FIFO from SCHED_NORMAL, so that * hotplug in operation may complete quickly in heavy loaded * conditions and new CPU will start handle the workload. */ switch_err = switch_to_rt_policy(); |
c6e5f9d7c ANDROID: cpu-hotp... |
1429 |
|
01b0f1970 cpu/mem hotplug: ... |
1430 1431 |
err = try_online_node(cpu_to_node(cpu)); if (err) |
c6e5f9d7c ANDROID: cpu-hotp... |
1432 |
goto switch_out; |
cf23422b9 cpu/mem hotplug: ... |
1433 |
|
d221938c0 cpu-hotplug: refc... |
1434 |
cpu_maps_update_begin(); |
e761b7725 cpu hotplug, sche... |
1435 1436 |
if (cpu_hotplug_disabled) { |
e3920fb42 [PATCH] Disable C... |
1437 |
err = -EBUSY; |
e761b7725 cpu hotplug, sche... |
1438 1439 |
goto out; } |
05736e4ac cpu/hotplug: Prov... |
1440 1441 1442 1443 |
if (!cpu_smt_allowed(cpu)) { err = -EPERM; goto out; } |
e761b7725 cpu hotplug, sche... |
1444 |
|
af1f40457 cpu/hotplug: Hand... |
1445 |
err = _cpu_up(cpu, 0, target); |
e761b7725 cpu hotplug, sche... |
1446 |
out: |
d221938c0 cpu-hotplug: refc... |
1447 |
cpu_maps_update_done(); |
c6e5f9d7c ANDROID: cpu-hotp... |
1448 1449 1450 1451 1452 1453 1454 1455 |
switch_out: if (!switch_err) { switch_err = switch_to_fair_policy(); if (switch_err) pr_err("Hotplug policy switch err=%d Task %s pid=%d ", switch_err, current->comm, current->pid); } |
e3920fb42 [PATCH] Disable C... |
1456 1457 |
return err; } |
af1f40457 cpu/hotplug: Hand... |
1458 |
|
33c3736ec cpu/hotplug: Hide... |
1459 1460 1461 1462 1463 1464 1465 1466 1467 |
/** * cpu_device_up - Bring up a cpu device * @dev: Pointer to the cpu device to online * * This function is meant to be used by device core cpu subsystem only. * * Other subsystems should use add_cpu() instead. */ int cpu_device_up(struct device *dev) |
af1f40457 cpu/hotplug: Hand... |
1468 |
{ |
33c3736ec cpu/hotplug: Hide... |
1469 |
return cpu_up(dev->id, CPUHP_ONLINE); |
af1f40457 cpu/hotplug: Hand... |
1470 |
} |
e3920fb42 [PATCH] Disable C... |
1471 |
|
93ef1429e cpu/hotplug: Add ... |
1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 |
int add_cpu(unsigned int cpu) { int ret; lock_device_hotplug(); ret = device_online(get_cpu_device(cpu)); unlock_device_hotplug(); return ret; } EXPORT_SYMBOL_GPL(add_cpu); |
d720f9860 cpu/hotplug: Prov... |
1483 1484 1485 1486 1487 1488 1489 1490 1491 |
/** * bringup_hibernate_cpu - Bring up the CPU that we hibernated on * @sleep_cpu: The cpu we hibernated on and should be brought up. * * On some architectures like arm64, we can hibernate on any CPU, but on * wake up the CPU we hibernated on might be offline as a side effect of * using maxcpus= for example. */ int bringup_hibernate_cpu(unsigned int sleep_cpu) |
af1f40457 cpu/hotplug: Hand... |
1492 |
{ |
d720f9860 cpu/hotplug: Prov... |
1493 1494 1495 1496 1497 |
int ret; if (!cpu_online(sleep_cpu)) { pr_info("Hibernated on a CPU that is offline! Bringing CPU up. "); |
33c3736ec cpu/hotplug: Hide... |
1498 |
ret = cpu_up(sleep_cpu, CPUHP_ONLINE); |
d720f9860 cpu/hotplug: Prov... |
1499 1500 1501 1502 1503 1504 1505 1506 |
if (ret) { pr_err("Failed to bring hibernate-CPU up! "); return ret; } } return 0; } |
b99a26593 cpu/hotplug: Move... |
1507 1508 1509 1510 1511 1512 1513 1514 |
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)) |
33c3736ec cpu/hotplug: Hide... |
1515 |
cpu_up(cpu, CPUHP_ONLINE); |
b99a26593 cpu/hotplug: Move... |
1516 |
} |
af1f40457 cpu/hotplug: Hand... |
1517 |
} |
e3920fb42 [PATCH] Disable C... |
1518 |
|
f3de4be9d PM: Fix dependenc... |
1519 |
#ifdef CONFIG_PM_SLEEP_SMP |
e0b582ec5 cpumask: convert ... |
1520 |
static cpumask_var_t frozen_cpus; |
e3920fb42 [PATCH] Disable C... |
1521 |
|
fb7fb84a0 cpu/hotplug: Remo... |
1522 |
int freeze_secondary_cpus(int primary) |
e3920fb42 [PATCH] Disable C... |
1523 |
{ |
d391e5522 cpu/hotplug: Allo... |
1524 |
int cpu, error = 0; |
e3920fb42 [PATCH] Disable C... |
1525 |
|
d221938c0 cpu-hotplug: refc... |
1526 |
cpu_maps_update_begin(); |
9ca12ac04 kernel/cpu: Allow... |
1527 |
if (primary == -1) { |
d391e5522 cpu/hotplug: Allo... |
1528 |
primary = cpumask_first(cpu_online_mask); |
9ca12ac04 kernel/cpu: Allow... |
1529 1530 1531 1532 1533 1534 |
if (!housekeeping_cpu(primary, HK_FLAG_TIMER)) primary = housekeeping_any_cpu(HK_FLAG_TIMER); } else { if (!cpu_online(primary)) primary = cpumask_first(cpu_online_mask); } |
9ee349ad6 sched: Fix set_cp... |
1535 1536 |
/* * We take down all of the non-boot CPUs in one shot to avoid races |
e3920fb42 [PATCH] Disable C... |
1537 1538 |
* with the userspace trying to use the CPU hotplug at the same time */ |
e0b582ec5 cpumask: convert ... |
1539 |
cpumask_clear(frozen_cpus); |
6ad4c1888 sched: Fix balanc... |
1540 |
|
84117da5b kernel/cpu.c: con... |
1541 1542 |
pr_info("Disabling non-boot CPUs ... "); |
e3920fb42 [PATCH] Disable C... |
1543 |
for_each_online_cpu(cpu) { |
d391e5522 cpu/hotplug: Allo... |
1544 |
if (cpu == primary) |
e3920fb42 [PATCH] Disable C... |
1545 |
continue; |
a66d955e9 cpu/hotplug: Abor... |
1546 |
|
fb7fb84a0 cpu/hotplug: Remo... |
1547 |
if (pm_wakeup_pending()) { |
a66d955e9 cpu/hotplug: Abor... |
1548 1549 1550 1551 1552 |
pr_info("Wakeup pending. Abort CPU freeze "); error = -EBUSY; break; } |
bb3632c61 PM / sleep: trace... |
1553 |
trace_suspend_resume(TPS("CPU_OFF"), cpu, true); |
af1f40457 cpu/hotplug: Hand... |
1554 |
error = _cpu_down(cpu, 1, CPUHP_OFFLINE); |
bb3632c61 PM / sleep: trace... |
1555 |
trace_suspend_resume(TPS("CPU_OFF"), cpu, false); |
feae3203d timers, init: Lim... |
1556 |
if (!error) |
e0b582ec5 cpumask: convert ... |
1557 |
cpumask_set_cpu(cpu, frozen_cpus); |
feae3203d timers, init: Lim... |
1558 |
else { |
84117da5b kernel/cpu.c: con... |
1559 1560 |
pr_err("Error taking CPU%d down: %d ", cpu, error); |
e3920fb42 [PATCH] Disable C... |
1561 1562 1563 |
break; } } |
86886e55b x86, intel_txt: I... |
1564 |
|
89af7ba57 cpu-hotplug: conv... |
1565 |
if (!error) |
e3920fb42 [PATCH] Disable C... |
1566 |
BUG_ON(num_online_cpus() > 1); |
89af7ba57 cpu-hotplug: conv... |
1567 |
else |
84117da5b kernel/cpu.c: con... |
1568 1569 |
pr_err("Non-boot CPUs are not disabled "); |
89af7ba57 cpu-hotplug: conv... |
1570 1571 1572 |
/* * Make sure the CPUs won't be enabled by someone else. We need to do |
565558558 cpu/hotplug: Remo... |
1573 1574 |
* this even in case of failure as all freeze_secondary_cpus() users are * supposed to do thaw_secondary_cpus() on the failure path. |
89af7ba57 cpu-hotplug: conv... |
1575 1576 |
*/ cpu_hotplug_disabled++; |
d221938c0 cpu-hotplug: refc... |
1577 |
cpu_maps_update_done(); |
e3920fb42 [PATCH] Disable C... |
1578 1579 |
return error; } |
565558558 cpu/hotplug: Remo... |
1580 |
void __weak arch_thaw_secondary_cpus_begin(void) |
d0af9eed5 x86, pat/mtrr: Re... |
1581 1582 |
{ } |
565558558 cpu/hotplug: Remo... |
1583 |
void __weak arch_thaw_secondary_cpus_end(void) |
d0af9eed5 x86, pat/mtrr: Re... |
1584 1585 |
{ } |
565558558 cpu/hotplug: Remo... |
1586 |
void thaw_secondary_cpus(void) |
e3920fb42 [PATCH] Disable C... |
1587 1588 |
{ int cpu, error; |
e6120dd58 ANDROID: cpu: sen... |
1589 |
struct device *cpu_device; |
e3920fb42 [PATCH] Disable C... |
1590 1591 |
/* Allow everyone to use the CPU hotplug again */ |
d221938c0 cpu-hotplug: refc... |
1592 |
cpu_maps_update_begin(); |
01b411590 cpu/hotplug: Hand... |
1593 |
__cpu_hotplug_enable(); |
e0b582ec5 cpumask: convert ... |
1594 |
if (cpumask_empty(frozen_cpus)) |
1d64b9cb1 [PATCH] Fix micro... |
1595 |
goto out; |
e3920fb42 [PATCH] Disable C... |
1596 |
|
84117da5b kernel/cpu.c: con... |
1597 1598 |
pr_info("Enabling non-boot CPUs ... "); |
d0af9eed5 x86, pat/mtrr: Re... |
1599 |
|
565558558 cpu/hotplug: Remo... |
1600 |
arch_thaw_secondary_cpus_begin(); |
d0af9eed5 x86, pat/mtrr: Re... |
1601 |
|
e0b582ec5 cpumask: convert ... |
1602 |
for_each_cpu(cpu, frozen_cpus) { |
bb3632c61 PM / sleep: trace... |
1603 |
trace_suspend_resume(TPS("CPU_ON"), cpu, true); |
af1f40457 cpu/hotplug: Hand... |
1604 |
error = _cpu_up(cpu, 1, CPUHP_ONLINE); |
bb3632c61 PM / sleep: trace... |
1605 |
trace_suspend_resume(TPS("CPU_ON"), cpu, false); |
e3920fb42 [PATCH] Disable C... |
1606 |
if (!error) { |
84117da5b kernel/cpu.c: con... |
1607 1608 |
pr_info("CPU%d is up ", cpu); |
e6120dd58 ANDROID: cpu: sen... |
1609 1610 1611 1612 1613 1614 1615 |
cpu_device = get_cpu_device(cpu); if (!cpu_device) pr_err("%s: failed to get cpu%d device ", __func__, cpu); else kobject_uevent(&cpu_device->kobj, KOBJ_ONLINE); |
e3920fb42 [PATCH] Disable C... |
1616 1617 |
continue; } |
84117da5b kernel/cpu.c: con... |
1618 1619 |
pr_warn("Error taking CPU%d up: %d ", cpu, error); |
e3920fb42 [PATCH] Disable C... |
1620 |
} |
d0af9eed5 x86, pat/mtrr: Re... |
1621 |
|
565558558 cpu/hotplug: Remo... |
1622 |
arch_thaw_secondary_cpus_end(); |
d0af9eed5 x86, pat/mtrr: Re... |
1623 |
|
e0b582ec5 cpumask: convert ... |
1624 |
cpumask_clear(frozen_cpus); |
1d64b9cb1 [PATCH] Fix micro... |
1625 |
out: |
d221938c0 cpu-hotplug: refc... |
1626 |
cpu_maps_update_done(); |
1da177e4c Linux-2.6.12-rc2 |
1627 |
} |
e0b582ec5 cpumask: convert ... |
1628 |
|
d7268a31c CPU: Add right qu... |
1629 |
static int __init alloc_frozen_cpus(void) |
e0b582ec5 cpumask: convert ... |
1630 1631 1632 1633 1634 1635 |
{ if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO)) return -ENOMEM; return 0; } core_initcall(alloc_frozen_cpus); |
79cfbdfa8 PM / Sleep: Fix r... |
1636 1637 |
/* |
79cfbdfa8 PM / Sleep: Fix r... |
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 |
* When callbacks for CPU hotplug notifications are being executed, we must * ensure that the state of the system with respect to the tasks being frozen * or not, as reported by the notification, remains unchanged *throughout the * duration* of the execution of the callbacks. * Hence we need to prevent the freezer from racing with regular CPU hotplug. * * This synchronization is implemented by mutually excluding regular CPU * hotplug and Suspend/Hibernate call paths by hooking onto the Suspend/ * Hibernate notifications. */ static int cpu_hotplug_pm_callback(struct notifier_block *nb, unsigned long action, void *ptr) { switch (action) { case PM_SUSPEND_PREPARE: case PM_HIBERNATION_PREPARE: |
16e53dbf1 CPU hotplug: prov... |
1656 |
cpu_hotplug_disable(); |
79cfbdfa8 PM / Sleep: Fix r... |
1657 1658 1659 1660 |
break; case PM_POST_SUSPEND: case PM_POST_HIBERNATION: |
16e53dbf1 CPU hotplug: prov... |
1661 |
cpu_hotplug_enable(); |
79cfbdfa8 PM / Sleep: Fix r... |
1662 1663 1664 1665 1666 1667 1668 1669 |
break; default: return NOTIFY_DONE; } return NOTIFY_OK; } |
d7268a31c CPU: Add right qu... |
1670 |
static int __init cpu_hotplug_pm_sync_init(void) |
79cfbdfa8 PM / Sleep: Fix r... |
1671 |
{ |
6e32d479d kernel/cpu.c: Add... |
1672 1673 1674 1675 1676 |
/* * cpu_hotplug_pm_callback has higher priority than x86 * bsp_pm_callback which depends on cpu_hotplug_pm_callback * to disable cpu hotplug to avoid cpu hotplug race. */ |
79cfbdfa8 PM / Sleep: Fix r... |
1677 1678 1679 1680 |
pm_notifier(cpu_hotplug_pm_callback, 0); return 0; } core_initcall(cpu_hotplug_pm_sync_init); |
f3de4be9d PM: Fix dependenc... |
1681 |
#endif /* CONFIG_PM_SLEEP_SMP */ |
68f4f1ec0 sched: Move cpu m... |
1682 |
|
8ce371f98 lockdep: Fix per-... |
1683 |
int __boot_cpu_id; |
68f4f1ec0 sched: Move cpu m... |
1684 |
#endif /* CONFIG_SMP */ |
b8d317d10 cpumask: make cpu... |
1685 |
|
cff7d378d cpu/hotplug: Conv... |
1686 |
/* Boot processor state steps */ |
17a2f1ced cpu/hotplug: Merg... |
1687 |
static struct cpuhp_step cpuhp_hp_states[] = { |
cff7d378d cpu/hotplug: Conv... |
1688 1689 |
[CPUHP_OFFLINE] = { .name = "offline", |
3c1627e99 cpu/hotplug: Repl... |
1690 1691 |
.startup.single = NULL, .teardown.single = NULL, |
cff7d378d cpu/hotplug: Conv... |
1692 1693 1694 |
}, #ifdef CONFIG_SMP [CPUHP_CREATE_THREADS]= { |
677f66465 cpu/hotplug: Make... |
1695 |
.name = "threads:prepare", |
3c1627e99 cpu/hotplug: Repl... |
1696 1697 |
.startup.single = smpboot_create_threads, .teardown.single = NULL, |
757c989b9 cpu/hotplug: Make... |
1698 |
.cant_stop = true, |
cff7d378d cpu/hotplug: Conv... |
1699 |
}, |
00e16c3d6 perf/core: Conver... |
1700 |
[CPUHP_PERF_PREPARE] = { |
3c1627e99 cpu/hotplug: Repl... |
1701 1702 1703 |
.name = "perf:prepare", .startup.single = perf_event_init_cpu, .teardown.single = perf_event_exit_cpu, |
00e16c3d6 perf/core: Conver... |
1704 |
}, |
7ee681b25 workqueue: Conver... |
1705 |
[CPUHP_WORKQUEUE_PREP] = { |
3c1627e99 cpu/hotplug: Repl... |
1706 1707 1708 |
.name = "workqueue:prepare", .startup.single = workqueue_prepare_cpu, .teardown.single = NULL, |
7ee681b25 workqueue: Conver... |
1709 |
}, |
27590dc17 hrtimer: Convert ... |
1710 |
[CPUHP_HRTIMERS_PREPARE] = { |
3c1627e99 cpu/hotplug: Repl... |
1711 1712 1713 |
.name = "hrtimers:prepare", .startup.single = hrtimers_prepare_cpu, .teardown.single = hrtimers_dead_cpu, |
27590dc17 hrtimer: Convert ... |
1714 |
}, |
31487f832 smp/cfd: Convert ... |
1715 |
[CPUHP_SMPCFD_PREPARE] = { |
677f66465 cpu/hotplug: Make... |
1716 |
.name = "smpcfd:prepare", |
3c1627e99 cpu/hotplug: Repl... |
1717 1718 |
.startup.single = smpcfd_prepare_cpu, .teardown.single = smpcfd_dead_cpu, |
31487f832 smp/cfd: Convert ... |
1719 |
}, |
e6d4989a9 relayfs: Convert ... |
1720 1721 1722 1723 1724 |
[CPUHP_RELAY_PREPARE] = { .name = "relay:prepare", .startup.single = relay_prepare_cpu, .teardown.single = NULL, }, |
6731d4f12 slab: Convert to ... |
1725 1726 1727 1728 |
[CPUHP_SLAB_PREPARE] = { .name = "slab:prepare", .startup.single = slab_prepare_cpu, .teardown.single = slab_dead_cpu, |
31487f832 smp/cfd: Convert ... |
1729 |
}, |
4df837425 rcu: Convert rcut... |
1730 |
[CPUHP_RCUTREE_PREP] = { |
677f66465 cpu/hotplug: Make... |
1731 |
.name = "RCU/tree:prepare", |
3c1627e99 cpu/hotplug: Repl... |
1732 1733 |
.startup.single = rcutree_prepare_cpu, .teardown.single = rcutree_dead_cpu, |
4df837425 rcu: Convert rcut... |
1734 |
}, |
d10ef6f93 cpu/hotplug: Docu... |
1735 |
/* |
4fae16dff timers/core: Corr... |
1736 1737 1738 1739 |
* On the tear-down path, timers_dead_cpu() must be invoked * before blk_mq_queue_reinit_notify() from notify_dead(), * otherwise a RCU stall occurs. */ |
26456f87a timers: Reinitial... |
1740 |
[CPUHP_TIMERS_PREPARE] = { |
d018031f5 cpu/hotplug: Clar... |
1741 |
.name = "timers:prepare", |
26456f87a timers: Reinitial... |
1742 |
.startup.single = timers_prepare_cpu, |
3c1627e99 cpu/hotplug: Repl... |
1743 |
.teardown.single = timers_dead_cpu, |
4fae16dff timers/core: Corr... |
1744 |
}, |
d10ef6f93 cpu/hotplug: Docu... |
1745 |
/* Kicks the plugged cpu into life */ |
cff7d378d cpu/hotplug: Conv... |
1746 1747 |
[CPUHP_BRINGUP_CPU] = { .name = "cpu:bringup", |
3c1627e99 cpu/hotplug: Repl... |
1748 |
.startup.single = bringup_cpu, |
bf2c59fce sched/core: Fix i... |
1749 |
.teardown.single = finish_cpu, |
757c989b9 cpu/hotplug: Make... |
1750 |
.cant_stop = true, |
4baa0afc6 cpu/hotplug: Conv... |
1751 |
}, |
d10ef6f93 cpu/hotplug: Docu... |
1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 |
/* Final state before CPU kills itself */ [CPUHP_AP_IDLE_DEAD] = { .name = "idle:dead", }, /* * Last state before CPU enters the idle loop to die. Transient state * for synchronization. */ [CPUHP_AP_OFFLINE] = { .name = "ap:offline", .cant_stop = true, }, |
9cf7243d5 sched: Make set_c... |
1764 1765 1766 |
/* First state is scheduler control. Interrupts are disabled */ [CPUHP_AP_SCHED_STARTING] = { .name = "sched:starting", |
3c1627e99 cpu/hotplug: Repl... |
1767 1768 |
.startup.single = sched_cpu_starting, .teardown.single = sched_cpu_dying, |
9cf7243d5 sched: Make set_c... |
1769 |
}, |
4df837425 rcu: Convert rcut... |
1770 |
[CPUHP_AP_RCUTREE_DYING] = { |
677f66465 cpu/hotplug: Make... |
1771 |
.name = "RCU/tree:dying", |
3c1627e99 cpu/hotplug: Repl... |
1772 1773 |
.startup.single = NULL, .teardown.single = rcutree_dying_cpu, |
4baa0afc6 cpu/hotplug: Conv... |
1774 |
}, |
46febd37f smp/hotplug: Move... |
1775 1776 1777 1778 1779 |
[CPUHP_AP_SMPCFD_DYING] = { .name = "smpcfd:dying", .startup.single = NULL, .teardown.single = smpcfd_dying_cpu, }, |
d10ef6f93 cpu/hotplug: Docu... |
1780 1781 1782 1783 1784 |
/* Entry state on starting. Interrupts enabled from here on. Transient * state for synchronsization */ [CPUHP_AP_ONLINE] = { .name = "ap:online", }, |
17a2f1ced cpu/hotplug: Merg... |
1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 |
/* * Handled on controll processor until the plugged processor manages * this itself. */ [CPUHP_TEARDOWN_CPU] = { .name = "cpu:teardown", .startup.single = NULL, .teardown.single = takedown_cpu, .cant_stop = true, }, |
d10ef6f93 cpu/hotplug: Docu... |
1795 |
/* Handle smpboot threads park/unpark */ |
1cf4f629d cpu/hotplug: Move... |
1796 |
[CPUHP_AP_SMPBOOT_THREADS] = { |
677f66465 cpu/hotplug: Make... |
1797 |
.name = "smpboot/threads:online", |
3c1627e99 cpu/hotplug: Repl... |
1798 |
.startup.single = smpboot_unpark_threads, |
c4de65696 cpu/hotplug: Make... |
1799 |
.teardown.single = smpboot_park_threads, |
1cf4f629d cpu/hotplug: Move... |
1800 |
}, |
c5cb83bb3 genirq/cpuhotplug... |
1801 1802 1803 1804 1805 |
[CPUHP_AP_IRQ_AFFINITY_ONLINE] = { .name = "irq/affinity:online", .startup.single = irq_affinity_online_cpu, .teardown.single = NULL, }, |
00e16c3d6 perf/core: Conver... |
1806 |
[CPUHP_AP_PERF_ONLINE] = { |
3c1627e99 cpu/hotplug: Repl... |
1807 1808 1809 |
.name = "perf:online", .startup.single = perf_event_init_cpu, .teardown.single = perf_event_exit_cpu, |
00e16c3d6 perf/core: Conver... |
1810 |
}, |
9cf57731b watchdog/softlock... |
1811 1812 1813 1814 1815 |
[CPUHP_AP_WATCHDOG_ONLINE] = { .name = "lockup_detector:online", .startup.single = lockup_detector_online_cpu, .teardown.single = lockup_detector_offline_cpu, }, |
7ee681b25 workqueue: Conver... |
1816 |
[CPUHP_AP_WORKQUEUE_ONLINE] = { |
3c1627e99 cpu/hotplug: Repl... |
1817 1818 1819 |
.name = "workqueue:online", .startup.single = workqueue_online_cpu, .teardown.single = workqueue_offline_cpu, |
7ee681b25 workqueue: Conver... |
1820 |
}, |
4df837425 rcu: Convert rcut... |
1821 |
[CPUHP_AP_RCUTREE_ONLINE] = { |
677f66465 cpu/hotplug: Make... |
1822 |
.name = "RCU/tree:online", |
3c1627e99 cpu/hotplug: Repl... |
1823 1824 |
.startup.single = rcutree_online_cpu, .teardown.single = rcutree_offline_cpu, |
4df837425 rcu: Convert rcut... |
1825 |
}, |
4baa0afc6 cpu/hotplug: Conv... |
1826 |
#endif |
d10ef6f93 cpu/hotplug: Docu... |
1827 1828 1829 |
/* * The dynamically registered state space is here */ |
aaddd7d1c sched/hotplug: Ma... |
1830 1831 1832 1833 |
#ifdef CONFIG_SMP /* Last state is scheduler control setting the cpu active */ [CPUHP_AP_ACTIVE] = { .name = "sched:active", |
3c1627e99 cpu/hotplug: Repl... |
1834 1835 |
.startup.single = sched_cpu_activate, .teardown.single = sched_cpu_deactivate, |
aaddd7d1c sched/hotplug: Ma... |
1836 1837 |
}, #endif |
d10ef6f93 cpu/hotplug: Docu... |
1838 |
/* CPU is fully up and running. */ |
4baa0afc6 cpu/hotplug: Conv... |
1839 1840 |
[CPUHP_ONLINE] = { .name = "online", |
3c1627e99 cpu/hotplug: Repl... |
1841 1842 |
.startup.single = NULL, .teardown.single = NULL, |
4baa0afc6 cpu/hotplug: Conv... |
1843 1844 |
}, }; |
5b7aa87e0 cpu/hotplug: Impl... |
1845 1846 1847 1848 1849 1850 1851 |
/* Sanity check for callbacks */ static int cpuhp_cb_check(enum cpuhp_state state) { if (state <= CPUHP_OFFLINE || state >= CPUHP_ONLINE) return -EINVAL; return 0; } |
dc280d936 cpu/hotplug: Prev... |
1852 1853 1854 1855 1856 1857 1858 |
/* * Returns a free for dynamic slot assignment of the Online state. The states * are protected by the cpuhp_slot_states mutex and an empty slot is identified * by having no name assigned. */ static int cpuhp_reserve_state(enum cpuhp_state state) { |
4205e4786 cpu/hotplug: Prov... |
1859 1860 |
enum cpuhp_state i, end; struct cpuhp_step *step; |
dc280d936 cpu/hotplug: Prev... |
1861 |
|
4205e4786 cpu/hotplug: Prov... |
1862 1863 |
switch (state) { case CPUHP_AP_ONLINE_DYN: |
17a2f1ced cpu/hotplug: Merg... |
1864 |
step = cpuhp_hp_states + CPUHP_AP_ONLINE_DYN; |
4205e4786 cpu/hotplug: Prov... |
1865 1866 1867 |
end = CPUHP_AP_ONLINE_DYN_END; break; case CPUHP_BP_PREPARE_DYN: |
17a2f1ced cpu/hotplug: Merg... |
1868 |
step = cpuhp_hp_states + CPUHP_BP_PREPARE_DYN; |
4205e4786 cpu/hotplug: Prov... |
1869 1870 1871 1872 1873 1874 1875 1876 |
end = CPUHP_BP_PREPARE_DYN_END; break; default: return -EINVAL; } for (i = state; i <= end; i++, step++) { if (!step->name) |
dc280d936 cpu/hotplug: Prev... |
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 |
return i; } WARN(1, "No more dynamic states available for CPU hotplug "); return -ENOSPC; } static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name, int (*startup)(unsigned int cpu), int (*teardown)(unsigned int cpu), bool multi_instance) |
5b7aa87e0 cpu/hotplug: Impl... |
1888 1889 1890 |
{ /* (Un)Install the callbacks for further cpu hotplug operations */ struct cpuhp_step *sp; |
dc280d936 cpu/hotplug: Prev... |
1891 |
int ret = 0; |
5b7aa87e0 cpu/hotplug: Impl... |
1892 |
|
0c96b2730 smp/hotplug: Hand... |
1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 |
/* * If name is NULL, then the state gets removed. * * CPUHP_AP_ONLINE_DYN and CPUHP_BP_PREPARE_DYN are handed out on * the first allocation from these dynamic ranges, so the removal * would trigger a new allocation and clear the wrong (already * empty) state, leaving the callbacks of the to be cleared state * dangling, which causes wreckage on the next hotplug operation. */ if (name && (state == CPUHP_AP_ONLINE_DYN || state == CPUHP_BP_PREPARE_DYN)) { |
dc280d936 cpu/hotplug: Prev... |
1904 1905 |
ret = cpuhp_reserve_state(state); if (ret < 0) |
dc434e056 cpu/hotplug: Seri... |
1906 |
return ret; |
dc280d936 cpu/hotplug: Prev... |
1907 1908 |
state = ret; } |
5b7aa87e0 cpu/hotplug: Impl... |
1909 |
sp = cpuhp_get_step(state); |
dc434e056 cpu/hotplug: Seri... |
1910 1911 |
if (name && sp->name) return -EBUSY; |
3c1627e99 cpu/hotplug: Repl... |
1912 1913 |
sp->startup.single = startup; sp->teardown.single = teardown; |
5b7aa87e0 cpu/hotplug: Impl... |
1914 |
sp->name = name; |
cf392d10b cpu/hotplug: Add ... |
1915 1916 |
sp->multi_instance = multi_instance; INIT_HLIST_HEAD(&sp->list); |
dc280d936 cpu/hotplug: Prev... |
1917 |
return ret; |
5b7aa87e0 cpu/hotplug: Impl... |
1918 1919 1920 1921 |
} static void *cpuhp_get_teardown_cb(enum cpuhp_state state) { |
3c1627e99 cpu/hotplug: Repl... |
1922 |
return cpuhp_get_step(state)->teardown.single; |
5b7aa87e0 cpu/hotplug: Impl... |
1923 |
} |
5b7aa87e0 cpu/hotplug: Impl... |
1924 1925 1926 1927 |
/* * Call the startup/teardown function for a step either on the AP or * on the current CPU. */ |
cf392d10b cpu/hotplug: Add ... |
1928 1929 |
static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup, struct hlist_node *node) |
5b7aa87e0 cpu/hotplug: Impl... |
1930 |
{ |
a724632ca cpu/hotplug: Rewo... |
1931 |
struct cpuhp_step *sp = cpuhp_get_step(state); |
5b7aa87e0 cpu/hotplug: Impl... |
1932 |
int ret; |
4dddfb5fa smp/hotplug: Rewr... |
1933 1934 1935 1936 |
/* * If there's nothing to do, we done. * Relies on the union for multi_instance. */ |
3c1627e99 cpu/hotplug: Repl... |
1937 1938 |
if ((bringup && !sp->startup.single) || (!bringup && !sp->teardown.single)) |
5b7aa87e0 cpu/hotplug: Impl... |
1939 |
return 0; |
5b7aa87e0 cpu/hotplug: Impl... |
1940 1941 1942 1943 |
/* * The non AP bound callbacks can fail on bringup. On teardown * e.g. module removal we crash for now. */ |
1cf4f629d cpu/hotplug: Move... |
1944 1945 |
#ifdef CONFIG_SMP if (cpuhp_is_ap_state(state)) |
cf392d10b cpu/hotplug: Add ... |
1946 |
ret = cpuhp_invoke_ap_callback(cpu, state, bringup, node); |
1cf4f629d cpu/hotplug: Move... |
1947 |
else |
96abb9685 smp/hotplug: Allo... |
1948 |
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
1cf4f629d cpu/hotplug: Move... |
1949 |
#else |
96abb9685 smp/hotplug: Allo... |
1950 |
ret = cpuhp_invoke_callback(cpu, state, bringup, node, NULL); |
1cf4f629d cpu/hotplug: Move... |
1951 |
#endif |
5b7aa87e0 cpu/hotplug: Impl... |
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 |
BUG_ON(ret && !bringup); return ret; } /* * Called from __cpuhp_setup_state on a recoverable failure. * * Note: The teardown callbacks for rollback are not allowed to fail! */ static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, |
cf392d10b cpu/hotplug: Add ... |
1962 |
struct hlist_node *node) |
5b7aa87e0 cpu/hotplug: Impl... |
1963 1964 |
{ int cpu; |
5b7aa87e0 cpu/hotplug: Impl... |
1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 |
/* Roll back the already executed steps on the other cpus */ for_each_present_cpu(cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int cpustate = st->state; if (cpu >= failedcpu) break; /* Did we invoke the startup call on that cpu ? */ if (cpustate >= state) |
cf392d10b cpu/hotplug: Add ... |
1975 |
cpuhp_issue_call(cpu, state, false, node); |
5b7aa87e0 cpu/hotplug: Impl... |
1976 1977 |
} } |
9805c6733 cpu/hotplug: Add ... |
1978 1979 1980 |
int __cpuhp_state_add_instance_cpuslocked(enum cpuhp_state state, struct hlist_node *node, bool invoke) |
cf392d10b cpu/hotplug: Add ... |
1981 1982 1983 1984 |
{ struct cpuhp_step *sp; int cpu; int ret; |
9805c6733 cpu/hotplug: Add ... |
1985 |
lockdep_assert_cpus_held(); |
cf392d10b cpu/hotplug: Add ... |
1986 1987 1988 |
sp = cpuhp_get_step(state); if (sp->multi_instance == false) return -EINVAL; |
dc434e056 cpu/hotplug: Seri... |
1989 |
mutex_lock(&cpuhp_state_mutex); |
cf392d10b cpu/hotplug: Add ... |
1990 |
|
3c1627e99 cpu/hotplug: Repl... |
1991 |
if (!invoke || !sp->startup.multi) |
cf392d10b cpu/hotplug: Add ... |
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 |
goto add_node; /* * Try to call the startup callback for each present cpu * depending on the hotplug state of the cpu. */ for_each_present_cpu(cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int cpustate = st->state; if (cpustate < state) continue; ret = cpuhp_issue_call(cpu, state, true, node); if (ret) { |
3c1627e99 cpu/hotplug: Repl... |
2007 |
if (sp->teardown.multi) |
cf392d10b cpu/hotplug: Add ... |
2008 |
cpuhp_rollback_install(cpu, state, node); |
dc434e056 cpu/hotplug: Seri... |
2009 |
goto unlock; |
cf392d10b cpu/hotplug: Add ... |
2010 2011 2012 2013 |
} } add_node: ret = 0; |
cf392d10b cpu/hotplug: Add ... |
2014 |
hlist_add_head(node, &sp->list); |
dc434e056 cpu/hotplug: Seri... |
2015 |
unlock: |
cf392d10b cpu/hotplug: Add ... |
2016 |
mutex_unlock(&cpuhp_state_mutex); |
9805c6733 cpu/hotplug: Add ... |
2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 |
return ret; } int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, bool invoke) { int ret; cpus_read_lock(); ret = __cpuhp_state_add_instance_cpuslocked(state, node, invoke); |
8f553c498 cpu/hotplug: Prov... |
2027 |
cpus_read_unlock(); |
cf392d10b cpu/hotplug: Add ... |
2028 2029 2030 |
return ret; } EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); |
5b7aa87e0 cpu/hotplug: Impl... |
2031 |
/** |
71def423f cpu/hotplug: Prov... |
2032 |
* __cpuhp_setup_state_cpuslocked - Setup the callbacks for an hotplug machine state |
dc280d936 cpu/hotplug: Prev... |
2033 2034 2035 2036 2037 2038 2039 |
* @state: The state to setup * @invoke: If true, the startup function is invoked for cpus where * cpu state >= @state * @startup: startup callback function * @teardown: teardown callback function * @multi_instance: State is set up for multiple instances which get * added afterwards. |
5b7aa87e0 cpu/hotplug: Impl... |
2040 |
* |
71def423f cpu/hotplug: Prov... |
2041 |
* The caller needs to hold cpus read locked while calling this function. |
512f09801 cpu/hotplug: Clar... |
2042 2043 2044 2045 2046 |
* Returns: * On success: * Positive state number if @state is CPUHP_AP_ONLINE_DYN * 0 for all other states * On failure: proper (negative) error code |
5b7aa87e0 cpu/hotplug: Impl... |
2047 |
*/ |
71def423f cpu/hotplug: Prov... |
2048 2049 2050 2051 2052 |
int __cpuhp_setup_state_cpuslocked(enum cpuhp_state state, const char *name, bool invoke, int (*startup)(unsigned int cpu), int (*teardown)(unsigned int cpu), bool multi_instance) |
5b7aa87e0 cpu/hotplug: Impl... |
2053 2054 |
{ int cpu, ret = 0; |
b9d9d6911 smp/hotplug: Undo... |
2055 |
bool dynstate; |
5b7aa87e0 cpu/hotplug: Impl... |
2056 |
|
71def423f cpu/hotplug: Prov... |
2057 |
lockdep_assert_cpus_held(); |
5b7aa87e0 cpu/hotplug: Impl... |
2058 2059 |
if (cpuhp_cb_check(state) || !name) return -EINVAL; |
dc434e056 cpu/hotplug: Seri... |
2060 |
mutex_lock(&cpuhp_state_mutex); |
5b7aa87e0 cpu/hotplug: Impl... |
2061 |
|
dc280d936 cpu/hotplug: Prev... |
2062 2063 |
ret = cpuhp_store_callbacks(state, name, startup, teardown, multi_instance); |
5b7aa87e0 cpu/hotplug: Impl... |
2064 |
|
b9d9d6911 smp/hotplug: Undo... |
2065 2066 2067 2068 2069 |
dynstate = state == CPUHP_AP_ONLINE_DYN; if (ret > 0 && dynstate) { state = ret; ret = 0; } |
dc280d936 cpu/hotplug: Prev... |
2070 |
if (ret || !invoke || !startup) |
5b7aa87e0 cpu/hotplug: Impl... |
2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 |
goto out; /* * Try to call the startup callback for each present cpu * depending on the hotplug state of the cpu. */ for_each_present_cpu(cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int cpustate = st->state; if (cpustate < state) continue; |
cf392d10b cpu/hotplug: Add ... |
2083 |
ret = cpuhp_issue_call(cpu, state, true, NULL); |
5b7aa87e0 cpu/hotplug: Impl... |
2084 |
if (ret) { |
a724632ca cpu/hotplug: Rewo... |
2085 |
if (teardown) |
cf392d10b cpu/hotplug: Add ... |
2086 2087 |
cpuhp_rollback_install(cpu, state, NULL); cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
5b7aa87e0 cpu/hotplug: Impl... |
2088 2089 2090 2091 |
goto out; } } out: |
dc434e056 cpu/hotplug: Seri... |
2092 |
mutex_unlock(&cpuhp_state_mutex); |
dc280d936 cpu/hotplug: Prev... |
2093 2094 2095 2096 |
/* * If the requested state is CPUHP_AP_ONLINE_DYN, return the * dynamically allocated state in case of success. */ |
b9d9d6911 smp/hotplug: Undo... |
2097 |
if (!ret && dynstate) |
5b7aa87e0 cpu/hotplug: Impl... |
2098 2099 2100 |
return state; return ret; } |
71def423f cpu/hotplug: Prov... |
2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 |
EXPORT_SYMBOL(__cpuhp_setup_state_cpuslocked); int __cpuhp_setup_state(enum cpuhp_state state, const char *name, bool invoke, int (*startup)(unsigned int cpu), int (*teardown)(unsigned int cpu), bool multi_instance) { int ret; cpus_read_lock(); ret = __cpuhp_setup_state_cpuslocked(state, name, invoke, startup, teardown, multi_instance); cpus_read_unlock(); return ret; } |
5b7aa87e0 cpu/hotplug: Impl... |
2117 |
EXPORT_SYMBOL(__cpuhp_setup_state); |
cf392d10b cpu/hotplug: Add ... |
2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 |
int __cpuhp_state_remove_instance(enum cpuhp_state state, struct hlist_node *node, bool invoke) { struct cpuhp_step *sp = cpuhp_get_step(state); int cpu; BUG_ON(cpuhp_cb_check(state)); if (!sp->multi_instance) return -EINVAL; |
8f553c498 cpu/hotplug: Prov... |
2128 |
cpus_read_lock(); |
dc434e056 cpu/hotplug: Seri... |
2129 |
mutex_lock(&cpuhp_state_mutex); |
cf392d10b cpu/hotplug: Add ... |
2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 |
if (!invoke || !cpuhp_get_teardown_cb(state)) goto remove; /* * Call the teardown callback for each present cpu depending * on the hotplug state of the cpu. This function is not * allowed to fail currently! */ for_each_present_cpu(cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int cpustate = st->state; if (cpustate >= state) cpuhp_issue_call(cpu, state, false, node); } remove: |
cf392d10b cpu/hotplug: Add ... |
2146 2147 |
hlist_del(node); mutex_unlock(&cpuhp_state_mutex); |
8f553c498 cpu/hotplug: Prov... |
2148 |
cpus_read_unlock(); |
cf392d10b cpu/hotplug: Add ... |
2149 2150 2151 2152 |
return 0; } EXPORT_SYMBOL_GPL(__cpuhp_state_remove_instance); |
dc434e056 cpu/hotplug: Seri... |
2153 |
|
5b7aa87e0 cpu/hotplug: Impl... |
2154 |
/** |
71def423f cpu/hotplug: Prov... |
2155 |
* __cpuhp_remove_state_cpuslocked - Remove the callbacks for an hotplug machine state |
5b7aa87e0 cpu/hotplug: Impl... |
2156 2157 2158 2159 |
* @state: The state to remove * @invoke: If true, the teardown function is invoked for cpus where * cpu state >= @state * |
71def423f cpu/hotplug: Prov... |
2160 |
* The caller needs to hold cpus read locked while calling this function. |
5b7aa87e0 cpu/hotplug: Impl... |
2161 2162 2163 |
* The teardown callback is currently not allowed to fail. Think * about module removal! */ |
71def423f cpu/hotplug: Prov... |
2164 |
void __cpuhp_remove_state_cpuslocked(enum cpuhp_state state, bool invoke) |
5b7aa87e0 cpu/hotplug: Impl... |
2165 |
{ |
cf392d10b cpu/hotplug: Add ... |
2166 |
struct cpuhp_step *sp = cpuhp_get_step(state); |
5b7aa87e0 cpu/hotplug: Impl... |
2167 2168 2169 |
int cpu; BUG_ON(cpuhp_cb_check(state)); |
71def423f cpu/hotplug: Prov... |
2170 |
lockdep_assert_cpus_held(); |
5b7aa87e0 cpu/hotplug: Impl... |
2171 |
|
dc434e056 cpu/hotplug: Seri... |
2172 |
mutex_lock(&cpuhp_state_mutex); |
cf392d10b cpu/hotplug: Add ... |
2173 2174 2175 2176 2177 2178 2179 |
if (sp->multi_instance) { WARN(!hlist_empty(&sp->list), "Error: Removing state %d which has instances left. ", state); goto remove; } |
a724632ca cpu/hotplug: Rewo... |
2180 |
if (!invoke || !cpuhp_get_teardown_cb(state)) |
5b7aa87e0 cpu/hotplug: Impl... |
2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 |
goto remove; /* * Call the teardown callback for each present cpu depending * on the hotplug state of the cpu. This function is not * allowed to fail currently! */ for_each_present_cpu(cpu) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int cpustate = st->state; if (cpustate >= state) |
cf392d10b cpu/hotplug: Add ... |
2193 |
cpuhp_issue_call(cpu, state, false, NULL); |
5b7aa87e0 cpu/hotplug: Impl... |
2194 2195 |
} remove: |
cf392d10b cpu/hotplug: Add ... |
2196 |
cpuhp_store_callbacks(state, NULL, NULL, NULL, false); |
dc434e056 cpu/hotplug: Seri... |
2197 |
mutex_unlock(&cpuhp_state_mutex); |
71def423f cpu/hotplug: Prov... |
2198 2199 2200 2201 2202 2203 2204 |
} EXPORT_SYMBOL(__cpuhp_remove_state_cpuslocked); void __cpuhp_remove_state(enum cpuhp_state state, bool invoke) { cpus_read_lock(); __cpuhp_remove_state_cpuslocked(state, invoke); |
8f553c498 cpu/hotplug: Prov... |
2205 |
cpus_read_unlock(); |
5b7aa87e0 cpu/hotplug: Impl... |
2206 2207 |
} EXPORT_SYMBOL(__cpuhp_remove_state); |
dc8d37ed3 cpu/SMT: Fix x86 ... |
2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 |
#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 |
98f8cdce1 cpu/hotplug: Add ... |
2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 |
#if defined(CONFIG_SYSFS) && defined(CONFIG_HOTPLUG_CPU) static ssize_t show_cpuhp_state(struct device *dev, struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d ", st->state); } static DEVICE_ATTR(state, 0444, show_cpuhp_state, NULL); |
757c989b9 cpu/hotplug: Make... |
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 |
static ssize_t write_cpuhp_target(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); struct cpuhp_step *sp; int target, ret; ret = kstrtoint(buf, 10, &target); if (ret) return ret; #ifdef CONFIG_CPU_HOTPLUG_STATE_CONTROL if (target < CPUHP_OFFLINE || target > CPUHP_ONLINE) return -EINVAL; #else if (target != CPUHP_OFFLINE && target != CPUHP_ONLINE) return -EINVAL; #endif ret = lock_device_hotplug_sysfs(); if (ret) return ret; mutex_lock(&cpuhp_state_mutex); sp = cpuhp_get_step(target); ret = !sp->name || sp->cant_stop ? -EINVAL : 0; mutex_unlock(&cpuhp_state_mutex); if (ret) |
40da1b11f cpu/hotplug: Drop... |
2318 |
goto out; |
757c989b9 cpu/hotplug: Make... |
2319 2320 |
if (st->state < target) |
33c3736ec cpu/hotplug: Hide... |
2321 |
ret = cpu_up(dev->id, target); |
757c989b9 cpu/hotplug: Make... |
2322 |
else |
33c3736ec cpu/hotplug: Hide... |
2323 |
ret = cpu_down(dev->id, target); |
40da1b11f cpu/hotplug: Drop... |
2324 |
out: |
757c989b9 cpu/hotplug: Make... |
2325 2326 2327 |
unlock_device_hotplug(); return ret ? ret : count; } |
98f8cdce1 cpu/hotplug: Add ... |
2328 2329 2330 2331 2332 2333 2334 2335 |
static ssize_t show_cpuhp_target(struct device *dev, struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d ", st->target); } |
757c989b9 cpu/hotplug: Make... |
2336 |
static DEVICE_ATTR(target, 0644, show_cpuhp_target, write_cpuhp_target); |
98f8cdce1 cpu/hotplug: Add ... |
2337 |
|
1db49484f smp/hotplug: Hotp... |
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 |
static ssize_t write_cpuhp_fail(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); struct cpuhp_step *sp; int fail, ret; ret = kstrtoint(buf, 10, &fail); if (ret) return ret; |
33d4a5a7a cpu/hotplug: Fix ... |
2350 2351 |
if (fail < CPUHP_OFFLINE || fail > CPUHP_ONLINE) return -EINVAL; |
1db49484f smp/hotplug: Hotp... |
2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 |
/* * Cannot fail STARTING/DYING callbacks. */ if (cpuhp_is_atomic_state(fail)) return -EINVAL; /* * Cannot fail anything that doesn't have callbacks. */ mutex_lock(&cpuhp_state_mutex); sp = cpuhp_get_step(fail); if (!sp->startup.single && !sp->teardown.single) ret = -EINVAL; mutex_unlock(&cpuhp_state_mutex); if (ret) return ret; st->fail = fail; return count; } static ssize_t show_cpuhp_fail(struct device *dev, struct device_attribute *attr, char *buf) { struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, dev->id); return sprintf(buf, "%d ", st->fail); } static DEVICE_ATTR(fail, 0644, show_cpuhp_fail, write_cpuhp_fail); |
98f8cdce1 cpu/hotplug: Add ... |
2384 2385 2386 |
static struct attribute *cpuhp_cpu_attrs[] = { &dev_attr_state.attr, &dev_attr_target.attr, |
1db49484f smp/hotplug: Hotp... |
2387 |
&dev_attr_fail.attr, |
98f8cdce1 cpu/hotplug: Add ... |
2388 2389 |
NULL }; |
993647a29 cpu/hotplug: Cons... |
2390 |
static const struct attribute_group cpuhp_cpu_attr_group = { |
98f8cdce1 cpu/hotplug: Add ... |
2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 |
.attrs = cpuhp_cpu_attrs, .name = "hotplug", NULL }; static ssize_t show_cpuhp_states(struct device *dev, struct device_attribute *attr, char *buf) { ssize_t cur, res = 0; int i; mutex_lock(&cpuhp_state_mutex); |
757c989b9 cpu/hotplug: Make... |
2403 |
for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { |
98f8cdce1 cpu/hotplug: Add ... |
2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 |
struct cpuhp_step *sp = cpuhp_get_step(i); if (sp->name) { cur = sprintf(buf, "%3d: %s ", i, sp->name); buf += cur; res += cur; } } mutex_unlock(&cpuhp_state_mutex); return res; } static DEVICE_ATTR(states, 0444, show_cpuhp_states, NULL); static struct attribute *cpuhp_cpu_root_attrs[] = { &dev_attr_states.attr, NULL }; |
993647a29 cpu/hotplug: Cons... |
2422 |
static const struct attribute_group cpuhp_cpu_root_attr_group = { |
98f8cdce1 cpu/hotplug: Add ... |
2423 2424 2425 2426 |
.attrs = cpuhp_cpu_root_attrs, .name = "hotplug", NULL }; |
05736e4ac cpu/hotplug: Prov... |
2427 |
#ifdef CONFIG_HOTPLUG_SMT |
05736e4ac cpu/hotplug: Prov... |
2428 |
static ssize_t |
de7b77e5b cpu/hotplug: Crea... |
2429 2430 |
__store_smt_control(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
05736e4ac cpu/hotplug: Prov... |
2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 |
{ int ctrlval, ret; if (sysfs_streq(buf, "on")) ctrlval = CPU_SMT_ENABLED; else if (sysfs_streq(buf, "off")) ctrlval = CPU_SMT_DISABLED; else if (sysfs_streq(buf, "forceoff")) ctrlval = CPU_SMT_FORCE_DISABLED; else return -EINVAL; if (cpu_smt_control == CPU_SMT_FORCE_DISABLED) return -EPERM; if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED) return -ENODEV; ret = lock_device_hotplug_sysfs(); if (ret) return ret; if (ctrlval != cpu_smt_control) { switch (ctrlval) { case CPU_SMT_ENABLED: |
215af5499 cpu/hotplug: Onli... |
2456 |
ret = cpuhp_smt_enable(); |
05736e4ac cpu/hotplug: Prov... |
2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 |
break; case CPU_SMT_DISABLED: case CPU_SMT_FORCE_DISABLED: ret = cpuhp_smt_disable(ctrlval); break; } } unlock_device_hotplug(); return ret ? ret : count; } |
de7b77e5b cpu/hotplug: Crea... |
2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 |
#else /* !CONFIG_HOTPLUG_SMT */ static ssize_t __store_smt_control(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { return -ENODEV; } #endif /* CONFIG_HOTPLUG_SMT */ static const char *smt_states[] = { [CPU_SMT_ENABLED] = "on", [CPU_SMT_DISABLED] = "off", [CPU_SMT_FORCE_DISABLED] = "forceoff", [CPU_SMT_NOT_SUPPORTED] = "notsupported", [CPU_SMT_NOT_IMPLEMENTED] = "notimplemented", }; static ssize_t show_smt_control(struct device *dev, struct device_attribute *attr, char *buf) { const char *state = smt_states[cpu_smt_control]; return snprintf(buf, PAGE_SIZE - 2, "%s ", state); } static ssize_t store_smt_control(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { return __store_smt_control(dev, attr, buf, count); } |
05736e4ac cpu/hotplug: Prov... |
2501 2502 2503 2504 2505 |
static DEVICE_ATTR(control, 0644, show_smt_control, store_smt_control); static ssize_t show_smt_active(struct device *dev, struct device_attribute *attr, char *buf) { |
de7b77e5b cpu/hotplug: Crea... |
2506 2507 |
return snprintf(buf, PAGE_SIZE - 2, "%d ", sched_smt_active()); |
05736e4ac cpu/hotplug: Prov... |
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 |
} static DEVICE_ATTR(active, 0444, show_smt_active, NULL); static struct attribute *cpuhp_smt_attrs[] = { &dev_attr_control.attr, &dev_attr_active.attr, NULL }; static const struct attribute_group cpuhp_smt_attr_group = { .attrs = cpuhp_smt_attrs, .name = "smt", NULL }; |
de7b77e5b cpu/hotplug: Crea... |
2522 |
static int __init cpu_smt_sysfs_init(void) |
05736e4ac cpu/hotplug: Prov... |
2523 |
{ |
05736e4ac cpu/hotplug: Prov... |
2524 2525 2526 |
return sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpuhp_smt_attr_group); } |
98f8cdce1 cpu/hotplug: Add ... |
2527 2528 2529 |
static int __init cpuhp_sysfs_init(void) { int cpu, ret; |
de7b77e5b cpu/hotplug: Crea... |
2530 |
ret = cpu_smt_sysfs_init(); |
05736e4ac cpu/hotplug: Prov... |
2531 2532 |
if (ret) return ret; |
98f8cdce1 cpu/hotplug: Add ... |
2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 |
ret = sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpuhp_cpu_root_attr_group); if (ret) return ret; for_each_possible_cpu(cpu) { struct device *dev = get_cpu_device(cpu); if (!dev) continue; ret = sysfs_create_group(&dev->kobj, &cpuhp_cpu_attr_group); if (ret) return ret; } return 0; } device_initcall(cpuhp_sysfs_init); |
de7b77e5b cpu/hotplug: Crea... |
2550 |
#endif /* CONFIG_SYSFS && CONFIG_HOTPLUG_CPU */ |
98f8cdce1 cpu/hotplug: Add ... |
2551 |
|
e56b3bc79 cpu masks: optimi... |
2552 2553 2554 2555 |
/* * cpu_bit_bitmap[] is a special, "compressed" data structure that * represents all NR_CPUS bits binary values of 1<<nr. * |
e0b582ec5 cpumask: convert ... |
2556 |
* It is used by cpumask_of() to get a constant address to a CPU |
e56b3bc79 cpu masks: optimi... |
2557 2558 |
* mask value that has a single bit set only. */ |
b8d317d10 cpumask: make cpu... |
2559 |
|
e56b3bc79 cpu masks: optimi... |
2560 |
/* cpu_bit_bitmap[0] is empty - so we can back into it */ |
4d51985e4 kernel/cpu.c: fix... |
2561 |
#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x)) |
e56b3bc79 cpu masks: optimi... |
2562 2563 2564 |
#define MASK_DECLARE_2(x) MASK_DECLARE_1(x), MASK_DECLARE_1(x+1) #define MASK_DECLARE_4(x) MASK_DECLARE_2(x), MASK_DECLARE_2(x+2) #define MASK_DECLARE_8(x) MASK_DECLARE_4(x), MASK_DECLARE_4(x+4) |
b8d317d10 cpumask: make cpu... |
2565 |
|
e56b3bc79 cpu masks: optimi... |
2566 2567 2568 2569 2570 2571 2572 |
const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = { MASK_DECLARE_8(0), MASK_DECLARE_8(8), MASK_DECLARE_8(16), MASK_DECLARE_8(24), #if BITS_PER_LONG > 32 MASK_DECLARE_8(32), MASK_DECLARE_8(40), MASK_DECLARE_8(48), MASK_DECLARE_8(56), |
b8d317d10 cpumask: make cpu... |
2573 2574 |
#endif }; |
e56b3bc79 cpu masks: optimi... |
2575 |
EXPORT_SYMBOL_GPL(cpu_bit_bitmap); |
2d3854a37 cpumask: introduc... |
2576 2577 2578 |
const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL; EXPORT_SYMBOL(cpu_all_bits); |
b3199c025 cpumask: switch o... |
2579 2580 |
#ifdef CONFIG_INIT_ALL_POSSIBLE |
4b804c85d kernel/cpu.c: exp... |
2581 |
struct cpumask __cpu_possible_mask __read_mostly |
c4c54dd1c kernel/cpu.c: cha... |
2582 |
= {CPU_BITS_ALL}; |
b3199c025 cpumask: switch o... |
2583 |
#else |
4b804c85d kernel/cpu.c: exp... |
2584 |
struct cpumask __cpu_possible_mask __read_mostly; |
b3199c025 cpumask: switch o... |
2585 |
#endif |
4b804c85d kernel/cpu.c: exp... |
2586 |
EXPORT_SYMBOL(__cpu_possible_mask); |
b3199c025 cpumask: switch o... |
2587 |
|
4b804c85d kernel/cpu.c: exp... |
2588 2589 |
struct cpumask __cpu_online_mask __read_mostly; EXPORT_SYMBOL(__cpu_online_mask); |
b3199c025 cpumask: switch o... |
2590 |
|
4b804c85d kernel/cpu.c: exp... |
2591 2592 |
struct cpumask __cpu_present_mask __read_mostly; EXPORT_SYMBOL(__cpu_present_mask); |
b3199c025 cpumask: switch o... |
2593 |
|
4b804c85d kernel/cpu.c: exp... |
2594 2595 |
struct cpumask __cpu_active_mask __read_mostly; EXPORT_SYMBOL(__cpu_active_mask); |
3fa415206 cpumask: make set... |
2596 |
|
0c09ab96f cpu/hotplug: Cach... |
2597 2598 |
atomic_t __num_online_cpus __read_mostly; EXPORT_SYMBOL(__num_online_cpus); |
3fa415206 cpumask: make set... |
2599 2600 |
void init_cpu_present(const struct cpumask *src) { |
c4c54dd1c kernel/cpu.c: cha... |
2601 |
cpumask_copy(&__cpu_present_mask, src); |
3fa415206 cpumask: make set... |
2602 2603 2604 2605 |
} void init_cpu_possible(const struct cpumask *src) { |
c4c54dd1c kernel/cpu.c: cha... |
2606 |
cpumask_copy(&__cpu_possible_mask, src); |
3fa415206 cpumask: make set... |
2607 2608 2609 2610 |
} void init_cpu_online(const struct cpumask *src) { |
c4c54dd1c kernel/cpu.c: cha... |
2611 |
cpumask_copy(&__cpu_online_mask, src); |
3fa415206 cpumask: make set... |
2612 |
} |
cff7d378d cpu/hotplug: Conv... |
2613 |
|
0c09ab96f cpu/hotplug: Cach... |
2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 |
void set_cpu_online(unsigned int cpu, bool online) { /* * atomic_inc/dec() is required to handle the horrid abuse of this * function by the reboot and kexec code which invoke it from * IPI/NMI broadcasts when shutting down CPUs. Invocation from * regular CPU hotplug is properly serialized. * * Note, that the fact that __num_online_cpus is of type atomic_t * does not protect readers which are not serialized against * concurrent hotplug operations. */ if (online) { if (!cpumask_test_and_set_cpu(cpu, &__cpu_online_mask)) atomic_inc(&__num_online_cpus); } else { if (cpumask_test_and_clear_cpu(cpu, &__cpu_online_mask)) atomic_dec(&__num_online_cpus); } } |
cff7d378d cpu/hotplug: Conv... |
2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 |
/* * Activate the first processor. */ void __init boot_cpu_init(void) { int cpu = smp_processor_id(); /* Mark the boot cpu "present", "online" etc for SMP and UP case */ set_cpu_online(cpu, true); set_cpu_active(cpu, true); set_cpu_present(cpu, true); set_cpu_possible(cpu, true); |
8ce371f98 lockdep: Fix per-... |
2646 2647 2648 2649 |
#ifdef CONFIG_SMP __boot_cpu_id = cpu; #endif |
cff7d378d cpu/hotplug: Conv... |
2650 2651 2652 2653 2654 |
} /* * Must be called _AFTER_ setting up the per_cpu areas */ |
b5b1404d0 init: rename and ... |
2655 |
void __init boot_cpu_hotplug_init(void) |
cff7d378d cpu/hotplug: Conv... |
2656 |
{ |
269777aa5 cpu/hotplug: Non-... |
2657 |
#ifdef CONFIG_SMP |
e797bda3f smp/hotplug: Trac... |
2658 |
cpumask_set_cpu(smp_processor_id(), &cpus_booted_once_mask); |
269777aa5 cpu/hotplug: Non-... |
2659 |
#endif |
0cc3cd216 cpu/hotplug: Boot... |
2660 |
this_cpu_write(cpuhp_state.state, CPUHP_ONLINE); |
cff7d378d cpu/hotplug: Conv... |
2661 |
} |
98af84529 cpu/speculation: ... |
2662 |
|
731dc9df9 cpu/speculation: ... |
2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 |
/* * These are used for a global "mitigations=" cmdline option for toggling * optional CPU mitigations. */ enum cpu_mitigations { CPU_MITIGATIONS_OFF, CPU_MITIGATIONS_AUTO, CPU_MITIGATIONS_AUTO_NOSMT, }; static enum cpu_mitigations cpu_mitigations __ro_after_init = CPU_MITIGATIONS_AUTO; |
98af84529 cpu/speculation: ... |
2675 2676 2677 2678 2679 2680 2681 2682 2683 |
static int __init mitigations_parse_cmdline(char *arg) { if (!strcmp(arg, "off")) cpu_mitigations = CPU_MITIGATIONS_OFF; else if (!strcmp(arg, "auto")) cpu_mitigations = CPU_MITIGATIONS_AUTO; else if (!strcmp(arg, "auto,nosmt")) cpu_mitigations = CPU_MITIGATIONS_AUTO_NOSMT; |
1bf727202 cpu/speculation: ... |
2684 2685 2686 2687 |
else pr_crit("Unsupported mitigations=%s, system may still be vulnerable ", arg); |
98af84529 cpu/speculation: ... |
2688 2689 2690 2691 |
return 0; } early_param("mitigations", mitigations_parse_cmdline); |
731dc9df9 cpu/speculation: ... |
2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 |
/* mitigations=off */ bool cpu_mitigations_off(void) { return cpu_mitigations == CPU_MITIGATIONS_OFF; } EXPORT_SYMBOL_GPL(cpu_mitigations_off); /* mitigations=auto,nosmt */ bool cpu_mitigations_auto_nosmt(void) { return cpu_mitigations == CPU_MITIGATIONS_AUTO_NOSMT; } EXPORT_SYMBOL_GPL(cpu_mitigations_auto_nosmt); |