Merge git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched

* git://git.kernel.org/pub/scm/linux/kernel/git/mingo/linux-2.6-sched:
  latencytop: change /proc task_struct access method
  latencytop: fix memory leak on latency proc file
  latencytop: fix kernel panic while reading latency proc file
  sched: add declaration of sched_tail to sched.h
  sched: fix signedness warnings in sched.c
  sched: clean up __pick_last_entity() a bit
  sched: remove duplicate code from sched_fair.c
  sched: make early bootup sched_clock() use safer

2 files changed, 15 insertions, 14 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index b387a8de26a5..f06950c8a6ce 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -668,6 +668,8 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
  */
 unsigned int sysctl_sched_rt_period = 1000000;
 
+static __read_mostly int scheduler_running;
+
 /*
  * part of the period that we allow rt tasks to run in us.
  * default: 0.95s
@@ -689,14 +691,16 @@ unsigned long long cpu_clock(int cpu)
         unsigned long flags;
         struct rq *rq;
 
-        local_irq_save(flags);
-        rq = cpu_rq(cpu);
         /*
          * Only call sched_clock() if the scheduler has already been
          * initialized (some code might call cpu_clock() very early):
          */
-        if (rq->idle)
-                update_rq_clock(rq);
+        if (unlikely(!scheduler_running))
+                return 0;
+
+        local_irq_save(flags);
+        rq = cpu_rq(cpu);
+        update_rq_clock(rq);
         now = rq->clock;
         local_irq_restore(flags);
 
@@ -3885,7 +3889,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev)
 asmlinkage void __sched schedule(void)
 {
         struct task_struct *prev, *next;
-        long *switch_count;
+        unsigned long *switch_count;
         struct rq *rq;
         int cpu;
 
@@ -7284,6 +7288,8 @@ void __init sched_init(void)
          * During early bootup we pretend to be a normal task:
          */
         current->sched_class = &fair_sched_class;
+
+        scheduler_running = 1;
 }
 
 #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 6c091d6e159d..c8e6492c5925 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -202,17 +202,12 @@ static struct sched_entity *__pick_next_entity(struct cfs_rq *cfs_rq)
 
 static inline struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
-        struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
-        struct sched_entity *se = NULL;
-        struct rb_node *parent;
+        struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
 
-        while (*link) {
-                parent = *link;
-                se = rb_entry(parent, struct sched_entity, run_node);
-                link = &parent->rb_right;
-        }
+        if (!last)
+                return NULL;
 
-        return se;
+        return rb_entry(last, struct sched_entity, run_node);
 }
 
 /**************************************************************