From eff9662547f358239b98dfc4a8e6905b494e14d6 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 29 Nov 2016 18:51:00 +0100 Subject: [PATCH] Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function" This reverts commit 23196f2e5f5d810578a772785807dcdc2b9fdce9. Now that struct kthread is kmalloc'ed and not longer on the task stack there is no need anymore to pin the stack. Signed-off-by: Oleg Nesterov Acked-by: Peter Zijlstra (Intel) Acked-by: Thomas Gleixner Cc: Chunming Zhou Cc: Roman Pen Cc: Petr Mladek Cc: Andy Lutomirski Cc: Tejun Heo Cc: Andy Lutomirski Cc: Alex Deucher Cc: Andrew Morton Link: http://lkml.kernel.org/r/20161129175100.GA5333@redhat.com Signed-off-by: Thomas Gleixner --- kernel/kthread.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/kernel/kthread.c b/kernel/kthread.c index 9d64b6526d0b..7891a940007d 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -88,7 +88,7 @@ void free_kthread_struct(struct task_struct *k) static struct kthread *to_live_kthread(struct task_struct *k) { struct completion *vfork = ACCESS_ONCE(k->vfork_done); - if (likely(vfork) && try_get_task_stack(k)) + if (likely(vfork)) return __to_kthread(vfork); return NULL; } @@ -473,10 +473,8 @@ void kthread_unpark(struct task_struct *k) { struct kthread *kthread = to_live_kthread(k); - if (kthread) { + if (kthread) __kthread_unpark(k, kthread); - put_task_stack(k); - } } EXPORT_SYMBOL_GPL(kthread_unpark); @@ -505,7 +503,6 @@ int kthread_park(struct task_struct *k) wait_for_completion(&kthread->parked); } } - put_task_stack(k); ret = 0; } return ret; @@ -541,7 +538,6 @@ int kthread_stop(struct task_struct *k) __kthread_unpark(k, kthread); wake_up_process(k); wait_for_completion(&kthread->exited); - put_task_stack(k); } ret = k->exit_code; put_task_struct(k); -- 2.20.1