mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-13 09:26:49 +07:00
dd56af42bd
Currently, the expedited grace-period primitives do get_online_cpus(). This greatly simplifies their implementation, but means that calls to them holding locks that are acquired by CPU-hotplug notifiers (to say nothing of calls to these primitives from CPU-hotplug notifiers) can deadlock. But this is starting to become inconvenient, as can be seen here: https://lkml.org/lkml/2014/8/5/754. The problem in this case is that some developers need to acquire a mutex from a CPU-hotplug notifier, but also need to hold it across a synchronize_rcu_expedited(). As noted above, this currently results in deadlock. This commit avoids the deadlock and retains the simplicity by creating a try_get_online_cpus(), which returns false if the get_online_cpus() reference count could not immediately be incremented. If a call to try_get_online_cpus() returns true, the expedited primitives operate as before. If a call returns false, the expedited primitives fall back to normal grace-period operations. This falling back of course results in increased grace-period latency, but only during times when CPU hotplug operations are actually in flight. The effect should therefore be negligible during normal operation. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Tested-by: Lan Tianyu <tianyu.lan@intel.com>
782 lines
19 KiB
C
782 lines
19 KiB
C
/* CPU control.
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* (C) 2001, 2002, 2003, 2004 Rusty Russell
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*
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* This code is licenced under the GPL.
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*/
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#include <linux/proc_fs.h>
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#include <linux/smp.h>
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#include <linux/init.h>
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#include <linux/notifier.h>
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#include <linux/sched.h>
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#include <linux/unistd.h>
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#include <linux/cpu.h>
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#include <linux/oom.h>
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#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>
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#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 <trace/events/power.h>
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#include "smpboot.h"
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#ifdef CONFIG_SMP
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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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/*
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* The following two APIs (cpu_maps_update_begin/done) must be used when
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* attempting to serialize the updates to cpu_online_mask & cpu_present_mask.
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* The APIs cpu_notifier_register_begin/done() must be used to protect CPU
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* hotplug callback (un)registration performed using __register_cpu_notifier()
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* or __unregister_cpu_notifier().
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*/
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void cpu_maps_update_begin(void)
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{
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mutex_lock(&cpu_add_remove_lock);
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}
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EXPORT_SYMBOL(cpu_notifier_register_begin);
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void cpu_maps_update_done(void)
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{
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mutex_unlock(&cpu_add_remove_lock);
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}
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EXPORT_SYMBOL(cpu_notifier_register_done);
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static RAW_NOTIFIER_HEAD(cpu_chain);
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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
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*/
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static int cpu_hotplug_disabled;
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#ifdef CONFIG_HOTPLUG_CPU
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static struct {
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struct task_struct *active_writer;
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struct mutex lock; /* Synchronizes accesses to refcount, */
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/*
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* Also blocks the new readers during
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* an ongoing cpu hotplug operation.
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*/
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int refcount;
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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struct lockdep_map dep_map;
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#endif
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} cpu_hotplug = {
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.active_writer = NULL,
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.lock = __MUTEX_INITIALIZER(cpu_hotplug.lock),
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.refcount = 0,
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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.dep_map = {.name = "cpu_hotplug.lock" },
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#endif
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};
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/* Lockdep annotations for get/put_online_cpus() and cpu_hotplug_begin/end() */
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#define cpuhp_lock_acquire_read() lock_map_acquire_read(&cpu_hotplug.dep_map)
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#define cpuhp_lock_acquire_tryread() \
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lock_map_acquire_tryread(&cpu_hotplug.dep_map)
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#define cpuhp_lock_acquire() lock_map_acquire(&cpu_hotplug.dep_map)
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#define cpuhp_lock_release() lock_map_release(&cpu_hotplug.dep_map)
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void get_online_cpus(void)
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{
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might_sleep();
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if (cpu_hotplug.active_writer == current)
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return;
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cpuhp_lock_acquire_read();
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mutex_lock(&cpu_hotplug.lock);
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cpu_hotplug.refcount++;
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mutex_unlock(&cpu_hotplug.lock);
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}
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EXPORT_SYMBOL_GPL(get_online_cpus);
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bool try_get_online_cpus(void)
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{
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if (cpu_hotplug.active_writer == current)
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return true;
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if (!mutex_trylock(&cpu_hotplug.lock))
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return false;
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cpuhp_lock_acquire_tryread();
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cpu_hotplug.refcount++;
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mutex_unlock(&cpu_hotplug.lock);
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return true;
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}
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EXPORT_SYMBOL_GPL(try_get_online_cpus);
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void put_online_cpus(void)
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{
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if (cpu_hotplug.active_writer == current)
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return;
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mutex_lock(&cpu_hotplug.lock);
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if (WARN_ON(!cpu_hotplug.refcount))
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cpu_hotplug.refcount++; /* try to fix things up */
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if (!--cpu_hotplug.refcount && unlikely(cpu_hotplug.active_writer))
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wake_up_process(cpu_hotplug.active_writer);
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mutex_unlock(&cpu_hotplug.lock);
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cpuhp_lock_release();
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}
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EXPORT_SYMBOL_GPL(put_online_cpus);
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/*
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* This ensures that the hotplug operation can begin only when the
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* refcount goes to zero.
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*
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* Note that during a cpu-hotplug operation, the new readers, if any,
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* will be blocked by the cpu_hotplug.lock
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*
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* Since cpu_hotplug_begin() is always called after invoking
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* cpu_maps_update_begin(), we can be sure that only one writer is active.
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*
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* Note that theoretically, there is a possibility of a livelock:
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* - Refcount goes to zero, last reader wakes up the sleeping
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* writer.
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* - Last reader unlocks the cpu_hotplug.lock.
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* - A new reader arrives at this moment, bumps up the refcount.
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* - The writer acquires the cpu_hotplug.lock finds the refcount
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* non zero and goes to sleep again.
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*
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* However, this is very difficult to achieve in practice since
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* get_online_cpus() not an api which is called all that often.
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*
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*/
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void cpu_hotplug_begin(void)
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{
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cpu_hotplug.active_writer = current;
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cpuhp_lock_acquire();
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for (;;) {
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mutex_lock(&cpu_hotplug.lock);
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if (likely(!cpu_hotplug.refcount))
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break;
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__set_current_state(TASK_UNINTERRUPTIBLE);
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mutex_unlock(&cpu_hotplug.lock);
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schedule();
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}
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}
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void cpu_hotplug_done(void)
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{
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cpu_hotplug.active_writer = NULL;
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mutex_unlock(&cpu_hotplug.lock);
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cpuhp_lock_release();
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}
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/*
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* Wait for currently running CPU hotplug operations to complete (if any) and
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* disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
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* the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
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* hotplug path before performing hotplug operations. So acquiring that lock
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* guarantees mutual exclusion from any currently running hotplug operations.
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*/
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void cpu_hotplug_disable(void)
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{
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cpu_maps_update_begin();
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cpu_hotplug_disabled = 1;
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cpu_maps_update_done();
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}
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void cpu_hotplug_enable(void)
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{
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cpu_maps_update_begin();
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cpu_hotplug_disabled = 0;
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cpu_maps_update_done();
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}
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#endif /* CONFIG_HOTPLUG_CPU */
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/* Need to know about CPUs going up/down? */
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int __ref register_cpu_notifier(struct notifier_block *nb)
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{
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int ret;
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cpu_maps_update_begin();
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ret = raw_notifier_chain_register(&cpu_chain, nb);
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cpu_maps_update_done();
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return ret;
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}
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int __ref __register_cpu_notifier(struct notifier_block *nb)
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{
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return raw_notifier_chain_register(&cpu_chain, nb);
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}
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static int __cpu_notify(unsigned long val, void *v, int nr_to_call,
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int *nr_calls)
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{
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int ret;
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ret = __raw_notifier_call_chain(&cpu_chain, val, v, nr_to_call,
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nr_calls);
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return notifier_to_errno(ret);
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}
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static int cpu_notify(unsigned long val, void *v)
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{
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return __cpu_notify(val, v, -1, NULL);
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}
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#ifdef CONFIG_HOTPLUG_CPU
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static void cpu_notify_nofail(unsigned long val, void *v)
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{
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BUG_ON(cpu_notify(val, v));
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}
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EXPORT_SYMBOL(register_cpu_notifier);
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EXPORT_SYMBOL(__register_cpu_notifier);
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void __ref unregister_cpu_notifier(struct notifier_block *nb)
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{
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cpu_maps_update_begin();
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raw_notifier_chain_unregister(&cpu_chain, nb);
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cpu_maps_update_done();
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}
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EXPORT_SYMBOL(unregister_cpu_notifier);
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void __ref __unregister_cpu_notifier(struct notifier_block *nb)
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{
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raw_notifier_chain_unregister(&cpu_chain, nb);
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}
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EXPORT_SYMBOL(__unregister_cpu_notifier);
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/**
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* clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
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* @cpu: a CPU id
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*
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* This function walks all processes, finds a valid mm struct for each one and
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* then clears a corresponding bit in mm's cpumask. While this all sounds
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* trivial, there are various non-obvious corner cases, which this function
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* tries to solve in a safe manner.
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*
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* Also note that the function uses a somewhat relaxed locking scheme, so it may
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* be called only for an already offlined CPU.
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*/
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void clear_tasks_mm_cpumask(int cpu)
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{
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struct task_struct *p;
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/*
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* This function is called after the cpu is taken down and marked
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* offline, so its not like new tasks will ever get this cpu set in
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* their mm mask. -- Peter Zijlstra
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* Thus, we may use rcu_read_lock() here, instead of grabbing
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* full-fledged tasklist_lock.
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*/
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WARN_ON(cpu_online(cpu));
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rcu_read_lock();
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for_each_process(p) {
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struct task_struct *t;
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/*
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* Main thread might exit, but other threads may still have
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* a valid mm. Find one.
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*/
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t = find_lock_task_mm(p);
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if (!t)
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continue;
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cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
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task_unlock(t);
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}
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rcu_read_unlock();
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}
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static inline void check_for_tasks(int dead_cpu)
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{
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struct task_struct *g, *p;
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read_lock_irq(&tasklist_lock);
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do_each_thread(g, p) {
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if (!p->on_rq)
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continue;
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/*
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* We do the check with unlocked task_rq(p)->lock.
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* Order the reading to do not warn about a task,
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* which was running on this cpu in the past, and
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* it's just been woken on another cpu.
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*/
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rmb();
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if (task_cpu(p) != dead_cpu)
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continue;
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pr_warn("Task %s (pid=%d) is on cpu %d (state=%ld, flags=%x)\n",
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p->comm, task_pid_nr(p), dead_cpu, p->state, p->flags);
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} while_each_thread(g, p);
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read_unlock_irq(&tasklist_lock);
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}
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struct take_cpu_down_param {
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unsigned long mod;
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void *hcpu;
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};
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/* Take this CPU down. */
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static int __ref take_cpu_down(void *_param)
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{
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struct take_cpu_down_param *param = _param;
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int err;
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/* Ensure this CPU doesn't handle any more interrupts. */
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err = __cpu_disable();
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if (err < 0)
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return err;
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cpu_notify(CPU_DYING | param->mod, param->hcpu);
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/* Park the stopper thread */
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kthread_park(current);
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return 0;
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}
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/* Requires cpu_add_remove_lock to be held */
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static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
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{
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int err, nr_calls = 0;
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void *hcpu = (void *)(long)cpu;
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unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
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struct take_cpu_down_param tcd_param = {
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.mod = mod,
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.hcpu = hcpu,
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};
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if (num_online_cpus() == 1)
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return -EBUSY;
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if (!cpu_online(cpu))
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return -EINVAL;
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cpu_hotplug_begin();
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err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
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if (err) {
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nr_calls--;
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__cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
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pr_warn("%s: attempt to take down CPU %u failed\n",
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__func__, cpu);
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goto out_release;
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}
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/*
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* By now we've cleared cpu_active_mask, wait for all preempt-disabled
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* and RCU users of this state to go away such that all new such users
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* will observe it.
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*
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* For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
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* not imply sync_sched(), so explicitly call both.
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*
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* Do sync before park smpboot threads to take care the rcu boost case.
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*/
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#ifdef CONFIG_PREEMPT
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synchronize_sched();
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#endif
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synchronize_rcu();
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smpboot_park_threads(cpu);
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/*
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* So now all preempt/rcu users must observe !cpu_active().
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*/
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err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
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if (err) {
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/* CPU didn't die: tell everyone. Can't complain. */
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smpboot_unpark_threads(cpu);
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cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
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goto out_release;
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}
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BUG_ON(cpu_online(cpu));
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/*
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* The migration_call() CPU_DYING callback will have removed all
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* runnable tasks from the cpu, there's only the idle task left now
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* that the migration thread is done doing the stop_machine thing.
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*
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* Wait for the stop thread to go away.
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*/
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while (!idle_cpu(cpu))
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cpu_relax();
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/* This actually kills the CPU. */
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__cpu_die(cpu);
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/* CPU is completely dead: tell everyone. Too late to complain. */
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cpu_notify_nofail(CPU_DEAD | mod, hcpu);
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check_for_tasks(cpu);
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out_release:
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cpu_hotplug_done();
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if (!err)
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cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
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return err;
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}
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int __ref cpu_down(unsigned int cpu)
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{
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int err;
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cpu_maps_update_begin();
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if (cpu_hotplug_disabled) {
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err = -EBUSY;
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goto out;
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}
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err = _cpu_down(cpu, 0);
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out:
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cpu_maps_update_done();
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return err;
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}
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EXPORT_SYMBOL(cpu_down);
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#endif /*CONFIG_HOTPLUG_CPU*/
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/* Requires cpu_add_remove_lock to be held */
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static int _cpu_up(unsigned int cpu, int tasks_frozen)
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{
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int ret, nr_calls = 0;
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void *hcpu = (void *)(long)cpu;
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unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
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struct task_struct *idle;
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cpu_hotplug_begin();
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if (cpu_online(cpu) || !cpu_present(cpu)) {
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ret = -EINVAL;
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goto out;
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}
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idle = idle_thread_get(cpu);
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if (IS_ERR(idle)) {
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ret = PTR_ERR(idle);
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goto out;
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}
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ret = smpboot_create_threads(cpu);
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if (ret)
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goto out;
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ret = __cpu_notify(CPU_UP_PREPARE | mod, hcpu, -1, &nr_calls);
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if (ret) {
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nr_calls--;
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pr_warn("%s: attempt to bring up CPU %u failed\n",
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__func__, cpu);
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goto out_notify;
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}
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/* Arch-specific enabling code. */
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ret = __cpu_up(cpu, idle);
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if (ret != 0)
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goto out_notify;
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BUG_ON(!cpu_online(cpu));
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/* Wake the per cpu threads */
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smpboot_unpark_threads(cpu);
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/* Now call notifier in preparation. */
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cpu_notify(CPU_ONLINE | mod, hcpu);
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out_notify:
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if (ret != 0)
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__cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
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out:
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cpu_hotplug_done();
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return ret;
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}
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int cpu_up(unsigned int cpu)
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{
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int err = 0;
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if (!cpu_possible(cpu)) {
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pr_err("can't online cpu %d because it is not configured as may-hotadd at boot time\n",
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cpu);
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#if defined(CONFIG_IA64)
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pr_err("please check additional_cpus= boot parameter\n");
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#endif
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return -EINVAL;
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}
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err = try_online_node(cpu_to_node(cpu));
|
|
if (err)
|
|
return err;
|
|
|
|
cpu_maps_update_begin();
|
|
|
|
if (cpu_hotplug_disabled) {
|
|
err = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
err = _cpu_up(cpu, 0);
|
|
|
|
out:
|
|
cpu_maps_update_done();
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(cpu_up);
|
|
|
|
#ifdef CONFIG_PM_SLEEP_SMP
|
|
static cpumask_var_t frozen_cpus;
|
|
|
|
int disable_nonboot_cpus(void)
|
|
{
|
|
int cpu, first_cpu, error = 0;
|
|
|
|
cpu_maps_update_begin();
|
|
first_cpu = cpumask_first(cpu_online_mask);
|
|
/*
|
|
* We take down all of the non-boot CPUs in one shot to avoid races
|
|
* with the userspace trying to use the CPU hotplug at the same time
|
|
*/
|
|
cpumask_clear(frozen_cpus);
|
|
|
|
pr_info("Disabling non-boot CPUs ...\n");
|
|
for_each_online_cpu(cpu) {
|
|
if (cpu == first_cpu)
|
|
continue;
|
|
trace_suspend_resume(TPS("CPU_OFF"), cpu, true);
|
|
error = _cpu_down(cpu, 1);
|
|
trace_suspend_resume(TPS("CPU_OFF"), cpu, false);
|
|
if (!error)
|
|
cpumask_set_cpu(cpu, frozen_cpus);
|
|
else {
|
|
pr_err("Error taking CPU%d down: %d\n", cpu, error);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!error) {
|
|
BUG_ON(num_online_cpus() > 1);
|
|
/* Make sure the CPUs won't be enabled by someone else */
|
|
cpu_hotplug_disabled = 1;
|
|
} else {
|
|
pr_err("Non-boot CPUs are not disabled\n");
|
|
}
|
|
cpu_maps_update_done();
|
|
return error;
|
|
}
|
|
|
|
void __weak arch_enable_nonboot_cpus_begin(void)
|
|
{
|
|
}
|
|
|
|
void __weak arch_enable_nonboot_cpus_end(void)
|
|
{
|
|
}
|
|
|
|
void __ref enable_nonboot_cpus(void)
|
|
{
|
|
int cpu, error;
|
|
|
|
/* Allow everyone to use the CPU hotplug again */
|
|
cpu_maps_update_begin();
|
|
cpu_hotplug_disabled = 0;
|
|
if (cpumask_empty(frozen_cpus))
|
|
goto out;
|
|
|
|
pr_info("Enabling non-boot CPUs ...\n");
|
|
|
|
arch_enable_nonboot_cpus_begin();
|
|
|
|
for_each_cpu(cpu, frozen_cpus) {
|
|
trace_suspend_resume(TPS("CPU_ON"), cpu, true);
|
|
error = _cpu_up(cpu, 1);
|
|
trace_suspend_resume(TPS("CPU_ON"), cpu, false);
|
|
if (!error) {
|
|
pr_info("CPU%d is up\n", cpu);
|
|
continue;
|
|
}
|
|
pr_warn("Error taking CPU%d up: %d\n", cpu, error);
|
|
}
|
|
|
|
arch_enable_nonboot_cpus_end();
|
|
|
|
cpumask_clear(frozen_cpus);
|
|
out:
|
|
cpu_maps_update_done();
|
|
}
|
|
|
|
static int __init alloc_frozen_cpus(void)
|
|
{
|
|
if (!alloc_cpumask_var(&frozen_cpus, GFP_KERNEL|__GFP_ZERO))
|
|
return -ENOMEM;
|
|
return 0;
|
|
}
|
|
core_initcall(alloc_frozen_cpus);
|
|
|
|
/*
|
|
* 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:
|
|
cpu_hotplug_disable();
|
|
break;
|
|
|
|
case PM_POST_SUSPEND:
|
|
case PM_POST_HIBERNATION:
|
|
cpu_hotplug_enable();
|
|
break;
|
|
|
|
default:
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
|
|
static int __init cpu_hotplug_pm_sync_init(void)
|
|
{
|
|
/*
|
|
* 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.
|
|
*/
|
|
pm_notifier(cpu_hotplug_pm_callback, 0);
|
|
return 0;
|
|
}
|
|
core_initcall(cpu_hotplug_pm_sync_init);
|
|
|
|
#endif /* CONFIG_PM_SLEEP_SMP */
|
|
|
|
/**
|
|
* notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
|
|
* @cpu: cpu that just started
|
|
*
|
|
* This function calls the cpu_chain notifiers with CPU_STARTING.
|
|
* 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)
|
|
{
|
|
unsigned long val = CPU_STARTING;
|
|
|
|
#ifdef CONFIG_PM_SLEEP_SMP
|
|
if (frozen_cpus != NULL && cpumask_test_cpu(cpu, frozen_cpus))
|
|
val = CPU_STARTING_FROZEN;
|
|
#endif /* CONFIG_PM_SLEEP_SMP */
|
|
cpu_notify(val, (void *)(long)cpu);
|
|
}
|
|
|
|
#endif /* CONFIG_SMP */
|
|
|
|
/*
|
|
* cpu_bit_bitmap[] is a special, "compressed" data structure that
|
|
* represents all NR_CPUS bits binary values of 1<<nr.
|
|
*
|
|
* It is used by cpumask_of() to get a constant address to a CPU
|
|
* mask value that has a single bit set only.
|
|
*/
|
|
|
|
/* cpu_bit_bitmap[0] is empty - so we can back into it */
|
|
#define MASK_DECLARE_1(x) [x+1][0] = (1UL << (x))
|
|
#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)
|
|
|
|
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),
|
|
#endif
|
|
};
|
|
EXPORT_SYMBOL_GPL(cpu_bit_bitmap);
|
|
|
|
const DECLARE_BITMAP(cpu_all_bits, NR_CPUS) = CPU_BITS_ALL;
|
|
EXPORT_SYMBOL(cpu_all_bits);
|
|
|
|
#ifdef CONFIG_INIT_ALL_POSSIBLE
|
|
static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly
|
|
= CPU_BITS_ALL;
|
|
#else
|
|
static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly;
|
|
#endif
|
|
const struct cpumask *const cpu_possible_mask = to_cpumask(cpu_possible_bits);
|
|
EXPORT_SYMBOL(cpu_possible_mask);
|
|
|
|
static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly;
|
|
const struct cpumask *const cpu_online_mask = to_cpumask(cpu_online_bits);
|
|
EXPORT_SYMBOL(cpu_online_mask);
|
|
|
|
static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly;
|
|
const struct cpumask *const cpu_present_mask = to_cpumask(cpu_present_bits);
|
|
EXPORT_SYMBOL(cpu_present_mask);
|
|
|
|
static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly;
|
|
const struct cpumask *const cpu_active_mask = to_cpumask(cpu_active_bits);
|
|
EXPORT_SYMBOL(cpu_active_mask);
|
|
|
|
void set_cpu_possible(unsigned int cpu, bool possible)
|
|
{
|
|
if (possible)
|
|
cpumask_set_cpu(cpu, to_cpumask(cpu_possible_bits));
|
|
else
|
|
cpumask_clear_cpu(cpu, to_cpumask(cpu_possible_bits));
|
|
}
|
|
|
|
void set_cpu_present(unsigned int cpu, bool present)
|
|
{
|
|
if (present)
|
|
cpumask_set_cpu(cpu, to_cpumask(cpu_present_bits));
|
|
else
|
|
cpumask_clear_cpu(cpu, to_cpumask(cpu_present_bits));
|
|
}
|
|
|
|
void set_cpu_online(unsigned int cpu, bool online)
|
|
{
|
|
if (online) {
|
|
cpumask_set_cpu(cpu, to_cpumask(cpu_online_bits));
|
|
cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
|
|
} else {
|
|
cpumask_clear_cpu(cpu, to_cpumask(cpu_online_bits));
|
|
}
|
|
}
|
|
|
|
void set_cpu_active(unsigned int cpu, bool active)
|
|
{
|
|
if (active)
|
|
cpumask_set_cpu(cpu, to_cpumask(cpu_active_bits));
|
|
else
|
|
cpumask_clear_cpu(cpu, to_cpumask(cpu_active_bits));
|
|
}
|
|
|
|
void init_cpu_present(const struct cpumask *src)
|
|
{
|
|
cpumask_copy(to_cpumask(cpu_present_bits), src);
|
|
}
|
|
|
|
void init_cpu_possible(const struct cpumask *src)
|
|
{
|
|
cpumask_copy(to_cpumask(cpu_possible_bits), src);
|
|
}
|
|
|
|
void init_cpu_online(const struct cpumask *src)
|
|
{
|
|
cpumask_copy(to_cpumask(cpu_online_bits), src);
|
|
}
|