sched/autogroup: Fix crash on reboot when autogroup is disabled

[firefly-linux-kernel-4.4.55.git] / kernel / sched / auto_group.c

diff --git a/kernel/sched/auto_group.c b/kernel/sched/auto_group.c
index 0984a21076a3ed8a37e56d5381bff6320d8fa5f2..0f1bacb005a4f5f2761b032dfec8a32e913fab54 100644 (file)
--- a/kernel/sched/auto_group.c
+++ b/kernel/sched/auto_group.c
@@ -110,6 +110,9 @@ out_fail:
 
 bool task_wants_autogroup(struct task_struct *p, struct task_group *tg)
 {
+       if (!sysctl_sched_autogroup_enabled)
+               return false;
+
        if (tg != &root_task_group)
                return false;
 
@@ -143,15 +146,11 @@ autogroup_move_group(struct task_struct *p, struct autogroup *ag)
 
        p->signal->autogroup = autogroup_kref_get(ag);
 
-       if (!ACCESS_ONCE(sysctl_sched_autogroup_enabled))
-               goto out;
-
        t = p;
        do {
                sched_move_task(t);
        } while_each_thread(p, t);
 
-out:
        unlock_task_sighand(p, &flags);
        autogroup_kref_put(prev);
 }
@@ -159,8 +158,11 @@ out:
 /* Allocates GFP_KERNEL, cannot be called under any spinlock */
 void sched_autogroup_create_attach(struct task_struct *p)
 {
-       struct autogroup *ag = autogroup_create();
+       struct autogroup *ag;
 
+       if (!sysctl_sched_autogroup_enabled)
+               return;
+       ag = autogroup_create();
        autogroup_move_group(p, ag);
        /* drop extra reference added by autogroup_create() */
        autogroup_kref_put(ag);
@@ -176,11 +178,15 @@ EXPORT_SYMBOL(sched_autogroup_detach);
 
 void sched_autogroup_fork(struct signal_struct *sig)
 {
+       if (!sysctl_sched_autogroup_enabled)
+               return;
        sig->autogroup = autogroup_task_get(current);
 }
 
 void sched_autogroup_exit(struct signal_struct *sig)
 {
+       if (!sysctl_sched_autogroup_enabled)
+               return;
        autogroup_kref_put(sig->autogroup);
 }
 
@@ -193,58 +199,6 @@ static int __init setup_autogroup(char *str)
 
 __setup("noautogroup", setup_autogroup);
 
-#ifdef CONFIG_PROC_FS
-
-int proc_sched_autogroup_set_nice(struct task_struct *p, int nice)
-{
-       static unsigned long next = INITIAL_JIFFIES;
-       struct autogroup *ag;
-       int err;
-
-       if (nice < -20 || nice > 19)
-               return -EINVAL;
-
-       err = security_task_setnice(current, nice);
-       if (err)
-               return err;
-
-       if (nice < 0 && !can_nice(current, nice))
-               return -EPERM;
-
-       /* this is a heavy operation taking global locks.. */
-       if (!capable(CAP_SYS_ADMIN) && time_before(jiffies, next))
-               return -EAGAIN;
-
-       next = HZ / 10 + jiffies;
-       ag = autogroup_task_get(p);
-
-       down_write(&ag->lock);
-       err = sched_group_set_shares(ag->tg, prio_to_weight[nice + 20]);
-       if (!err)
-               ag->nice = nice;
-       up_write(&ag->lock);
-
-       autogroup_kref_put(ag);
-
-       return err;
-}
-
-void proc_sched_autogroup_show_task(struct task_struct *p, struct seq_file *m)
-{
-       struct autogroup *ag = autogroup_task_get(p);
-
-       if (!task_group_is_autogroup(ag->tg))
-               goto out;
-
-       down_read(&ag->lock);
-       seq_printf(m, "/autogroup-%ld nice %d\n", ag->id, ag->nice);
-       up_read(&ag->lock);
-
-out:
-       autogroup_kref_put(ag);
-}
-#endif /* CONFIG_PROC_FS */
-
 #ifdef CONFIG_SCHED_DEBUG
 int autogroup_path(struct task_group *tg, char *buf, int buflen)
 {