Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Misc scheduler fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/core: Reset task's lockless wake-queues on fork()
  sched/core: Fix unserialized r-m-w scribbling stuff
  sched/core: Check tgid in is_global_init()
  sched/fair: Fix multiplication overflow on 32-bit systems

Author: torvalds

include/linux/sched.h

@@ -1455,14 +1455,15 @@ struct task_struct {
 	/* Used for emulating ABI behavior of previous Linux versions */
 	unsigned int personality;
 
-	unsigned in_execve:1;	/* Tell the LSMs that the process is doing an
-				 * execve */
-	unsigned in_iowait:1;
-
-	/* Revert to default priority/policy when forking */
+	/* scheduler bits, serialized by scheduler locks */
 	unsigned sched_reset_on_fork:1;
 	unsigned sched_contributes_to_load:1;
 	unsigned sched_migrated:1;
+	unsigned :0; /* force alignment to the next boundary */
+
+	/* unserialized, strictly 'current' */
+	unsigned in_execve:1; /* bit to tell LSMs we're in execve */
+	unsigned in_iowait:1;
 #ifdef CONFIG_MEMCG
 	unsigned memcg_may_oom:1;
 #endif
@@ -2002,7 +2003,8 @@ static inline int pid_alive(const struct task_struct *p)
 }
 
 /**
- * is_global_init - check if a task structure is init
+ * is_global_init - check if a task structure is init. Since init
+ * is free to have sub-threads we need to check tgid.
  * @tsk: Task structure to be checked.
  *
  * Check if a task structure is the first user space task the kernel created.
@@ -2011,7 +2013,7 @@ static inline int pid_alive(const struct task_struct *p)
  */
 static inline int is_global_init(struct task_struct *tsk)
 {
-	return tsk->pid == 1;
+	return task_tgid_nr(tsk) == 1;
 }
 
 extern struct pid *cad_pid;

kernel/fork.c

@@ -380,6 +380,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
 #endif
 	tsk->splice_pipe = NULL;
 	tsk->task_frag.page = NULL;
+	tsk->wake_q.next = NULL;
 
 	account_kernel_stack(ti, 1);
 

kernel/sched/fair.c

@@ -2689,7 +2689,7 @@ static inline int update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 	int decayed, removed = 0;
 
 	if (atomic_long_read(&cfs_rq->removed_load_avg)) {
-		long r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
+		s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
 		sa->load_avg = max_t(long, sa->load_avg - r, 0);
 		sa->load_sum = max_t(s64, sa->load_sum - r * LOAD_AVG_MAX, 0);
 		removed = 1;