forked from mirrors/linux
		
	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>
		
	
			
		
			
				
	
	
		
			61 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _LINUX_SMPBOOT_H
 | 
						|
#define _LINUX_SMPBOOT_H
 | 
						|
 | 
						|
#include <linux/types.h>
 | 
						|
 | 
						|
struct task_struct;
 | 
						|
/* Cookie handed to the thread_fn*/
 | 
						|
struct smpboot_thread_data;
 | 
						|
 | 
						|
/**
 | 
						|
 * struct smp_hotplug_thread - CPU hotplug related thread descriptor
 | 
						|
 * @store:		Pointer to per cpu storage for the task pointers
 | 
						|
 * @list:		List head for core management
 | 
						|
 * @thread_should_run:	Check whether the thread should run or not. Called with
 | 
						|
 *			preemption disabled.
 | 
						|
 * @thread_fn:		The associated thread function
 | 
						|
 * @create:		Optional setup function, called when the thread gets
 | 
						|
 *			created (Not called from the thread context)
 | 
						|
 * @setup:		Optional setup function, called when the thread gets
 | 
						|
 *			operational the first time
 | 
						|
 * @cleanup:		Optional cleanup function, called when the thread
 | 
						|
 *			should stop (module exit)
 | 
						|
 * @park:		Optional park function, called when the thread is
 | 
						|
 *			parked (cpu offline)
 | 
						|
 * @unpark:		Optional unpark function, called when the thread is
 | 
						|
 *			unparked (cpu online)
 | 
						|
 * @cpumask:		Internal state.  To update which threads are unparked,
 | 
						|
 *			call smpboot_update_cpumask_percpu_thread().
 | 
						|
 * @selfparking:	Thread is not parked by the park function.
 | 
						|
 * @thread_comm:	The base name of the thread
 | 
						|
 */
 | 
						|
struct smp_hotplug_thread {
 | 
						|
	struct task_struct __percpu	**store;
 | 
						|
	struct list_head		list;
 | 
						|
	int				(*thread_should_run)(unsigned int cpu);
 | 
						|
	void				(*thread_fn)(unsigned int cpu);
 | 
						|
	void				(*create)(unsigned int cpu);
 | 
						|
	void				(*setup)(unsigned int cpu);
 | 
						|
	void				(*cleanup)(unsigned int cpu, bool online);
 | 
						|
	void				(*park)(unsigned int cpu);
 | 
						|
	void				(*unpark)(unsigned int cpu);
 | 
						|
	cpumask_var_t			cpumask;
 | 
						|
	bool				selfparking;
 | 
						|
	const char			*thread_comm;
 | 
						|
};
 | 
						|
 | 
						|
int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
 | 
						|
					   const struct cpumask *cpumask);
 | 
						|
 | 
						|
static inline int
 | 
						|
smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
 | 
						|
{
 | 
						|
	return smpboot_register_percpu_thread_cpumask(plug_thread,
 | 
						|
						      cpu_possible_mask);
 | 
						|
}
 | 
						|
 | 
						|
void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread);
 | 
						|
int smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
 | 
						|
					 const struct cpumask *);
 | 
						|
 | 
						|
#endif
 |