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

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  llist: Add back llist_add_batch() and llist_del_first() prototypes
  sched: Don't use tasklist_lock for debug prints
  sched: Warn on rt throttling
  sched: Unify the ->cpus_allowed mask copy
  sched: Wrap scheduler p->cpus_allowed access
  sched: Request for idle balance during nohz idle load balance
  sched: Use resched IPI to kick off the nohz idle balance
  sched: Fix idle_cpu()
  llist: Remove cpu_relax() usage in cmpxchg loops
  sched: Convert to struct llist
  llist: Add llist_next()
  irq_work: Use llist in the struct irq_work logic
  llist: Return whether list is empty before adding in llist_add()
  llist: Move cpu_relax() to after the cmpxchg()
  llist: Remove the platform-dependent NMI checks
  llist: Make some llist functions inline
  sched, tracing: Show PREEMPT_ACTIVE state in trace_sched_switch
  sched: Remove redundant test in check_preempt_tick()
  sched: Add documentation for bandwidth control
  sched: Return unused runtime on group dequeue
  ...

1 files changed, 17 insertions, 57 deletions

diff --git a/lib/llist.c b/lib/llist.c
index da445724fa1f..700cff77a387 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -3,8 +3,8 @@
  *
  * The basic atomic operation of this list is cmpxchg on long.  On
  * architectures that don't have NMI-safe cmpxchg implementation, the
- * list can NOT be used in NMI handler.  So code uses the list in NMI
- * handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
+ * list can NOT be used in NMI handlers.  So code that uses the list in
+ * an NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
  *
  * Copyright 2010,2011 Intel Corp.
  *   Author: Huang Ying <ying.huang@intel.com>
@@ -30,48 +30,28 @@
 #include <asm/system.h>
 
 /**
- * llist_add - add a new entry
- * @new:	new entry to be added
- * @head:	the head for your lock-less list
- */
-void llist_add(struct llist_node *new, struct llist_head *head)
-{
-	struct llist_node *entry, *old_entry;
-
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-	BUG_ON(in_nmi());
-#endif
-
-	entry = head->first;
-	do {
-		old_entry = entry;
-		new->next = entry;
-		cpu_relax();
-	} while ((entry = cmpxchg(&head->first, old_entry, new)) != old_entry);
-}
-EXPORT_SYMBOL_GPL(llist_add);
-
-/**
  * llist_add_batch - add several linked entries in batch
  * @new_first:	first entry in batch to be added
  * @new_last:	last entry in batch to be added
  * @head:	the head for your lock-less list
+ *
+ * Return whether list is empty before adding.
  */
-void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
+bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
 		     struct llist_head *head)
 {
 	struct llist_node *entry, *old_entry;
 
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-	BUG_ON(in_nmi());
-#endif
-
 	entry = head->first;
-	do {
+	for (;;) {
 		old_entry = entry;
 		new_last->next = entry;
-		cpu_relax();
-	} while ((entry = cmpxchg(&head->first, old_entry, new_first)) != old_entry);
+		entry = cmpxchg(&head->first, old_entry, new_first);
+		if (entry == old_entry)
+			break;
+	}
+
+	return old_entry == NULL;
 }
 EXPORT_SYMBOL_GPL(llist_add_batch);
 
@@ -93,37 +73,17 @@ struct llist_node *llist_del_first(struct llist_head *head)
 {
 	struct llist_node *entry, *old_entry, *next;
 
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-	BUG_ON(in_nmi());
-#endif
-
 	entry = head->first;
-	do {
+	for (;;) {
 		if (entry == NULL)
 			return NULL;
 		old_entry = entry;
 		next = entry->next;
-		cpu_relax();
-	} while ((entry = cmpxchg(&head->first, old_entry, next)) != old_entry);
+		entry = cmpxchg(&head->first, old_entry, next);
+		if (entry == old_entry)
+			break;
+	}
 
 	return entry;
 }
 EXPORT_SYMBOL_GPL(llist_del_first);
-
-/**
- * llist_del_all - delete all entries from lock-less list
- * @head:	the head of lock-less list to delete all entries
- *
- * If list is empty, return NULL, otherwise, delete all entries and
- * return the pointer to the first entry.  The order of entries
- * deleted is from the newest to the oldest added one.
- */
-struct llist_node *llist_del_all(struct llist_head *head)
-{
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-	BUG_ON(in_nmi());
-#endif
-
-	return xchg(&head->first, NULL);
-}
-EXPORT_SYMBOL_GPL(llist_del_all);