c00166d87e
1. Change smpboot_unpark_thread() to check ->selfparking, just
like smpboot_park_thread() does.
2. Introduce stop_machine_unpark() which sets ->enabled and calls
kthread_unpark().
3. Change smpboot_thread_call() and cpu_stop_init() to call
stop_machine_unpark() by hand.
This way:
- IMO the ->selfparking logic becomes more consistent.
- We can kill the smp_hotplug_thread->pre_unpark() method.
- We can easily unpark the stopper thread earlier. Say, we
can move stop_machine_unpark() from smpboot_thread_call()
to sched_cpu_active() as Peter suggests.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20151009160049.GA10166@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
62 lines
2.1 KiB
C
62 lines
2.1 KiB
C
#ifndef _LINUX_SMPBOOT_H
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#define _LINUX_SMPBOOT_H
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#include <linux/types.h>
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struct task_struct;
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/* Cookie handed to the thread_fn*/
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struct smpboot_thread_data;
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/**
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* struct smp_hotplug_thread - CPU hotplug related thread descriptor
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* @store: Pointer to per cpu storage for the task pointers
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* @list: List head for core management
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* @thread_should_run: Check whether the thread should run or not. Called with
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* preemption disabled.
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* @thread_fn: The associated thread function
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* @create: Optional setup function, called when the thread gets
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* created (Not called from the thread context)
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* @setup: Optional setup function, called when the thread gets
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* operational the first time
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* @cleanup: Optional cleanup function, called when the thread
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* should stop (module exit)
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* @park: Optional park function, called when the thread is
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* parked (cpu offline)
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* @unpark: Optional unpark function, called when the thread is
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* unparked (cpu online)
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* @cpumask: Internal state. To update which threads are unparked,
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* call smpboot_update_cpumask_percpu_thread().
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* @selfparking: Thread is not parked by the park function.
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* @thread_comm: The base name of the thread
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*/
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struct smp_hotplug_thread {
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struct task_struct __percpu **store;
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struct list_head list;
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int (*thread_should_run)(unsigned int cpu);
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void (*thread_fn)(unsigned int cpu);
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void (*create)(unsigned int cpu);
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void (*setup)(unsigned int cpu);
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void (*cleanup)(unsigned int cpu, bool online);
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void (*park)(unsigned int cpu);
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void (*unpark)(unsigned int cpu);
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cpumask_var_t cpumask;
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bool selfparking;
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const char *thread_comm;
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};
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int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
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const struct cpumask *cpumask);
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static inline int
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smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
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{
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return smpboot_register_percpu_thread_cpumask(plug_thread,
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cpu_possible_mask);
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}
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void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread);
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int smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
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const struct cpumask *);
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#endif
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