From c00166d87e730088d919814020e96ffed129d0d1 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 9 Oct 2015 18:00:49 +0200 Subject: stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() 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 Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Rik van Riel Cc: Tejun Heo Cc: Thomas Gleixner Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151009160049.GA10166@redhat.com Signed-off-by: Ingo Molnar --- kernel/smpboot.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel/smpboot.c') diff --git a/kernel/smpboot.c b/kernel/smpboot.c index a818cbc73e14..d264f59bff56 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -222,9 +222,8 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp { struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu); - if (ht->pre_unpark) - ht->pre_unpark(cpu); - kthread_unpark(tsk); + if (!ht->selfparking) + kthread_unpark(tsk); } void smpboot_unpark_threads(unsigned int cpu) -- cgit v1.2.3