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:
  [PATCH] sched: debug feature - make the sched-domains tree runtime-tweakable
  [PATCH] sched: add above_background_load() function
  [PATCH] sched: update Documentation/sched-stats.txt
  [PATCH] sched: mark sysrq_sched_debug_show() static
  [PATCH] sched: make cpu_clock() not use the rq clock
  [PATCH] sched: remove unused rq->load_balance_class
  [PATCH] sched: arch preempt notifier mechanism
  [PATCH] sched: increase SCHED_LOAD_SCALE_FUZZ

2 files changed, 66 insertions, 1 deletions

diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index d0926d63406c..484988ed301e 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -8,6 +8,7 @@
 
 #include <linux/thread_info.h>
 #include <linux/linkage.h>
+#include <linux/list.h>
 
 #ifdef CONFIG_DEBUG_PREEMPT
   extern void fastcall add_preempt_count(int val);
@@ -60,4 +61,47 @@ do { \
 
 #endif
 
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+
+struct preempt_notifier;
+
+/**
+ * preempt_ops - notifiers called when a task is preempted and rescheduled
+ * @sched_in: we're about to be rescheduled:
+ *    notifier: struct preempt_notifier for the task being scheduled
+ *    cpu:  cpu we're scheduled on
+ * @sched_out: we've just been preempted
+ *    notifier: struct preempt_notifier for the task being preempted
+ *    next: the task that's kicking us out
+ */
+struct preempt_ops {
+        void (*sched_in)(struct preempt_notifier *notifier, int cpu);
+        void (*sched_out)(struct preempt_notifier *notifier,
+                          struct task_struct *next);
+};
+
+/**
+ * preempt_notifier - key for installing preemption notifiers
+ * @link: internal use
+ * @ops: defines the notifier functions to be called
+ *
+ * Usually used in conjunction with container_of().
+ */
+struct preempt_notifier {
+        struct hlist_node link;
+        struct preempt_ops *ops;
+};
+
+void preempt_notifier_register(struct preempt_notifier *notifier);
+void preempt_notifier_unregister(struct preempt_notifier *notifier);
+
+static inline void preempt_notifier_init(struct preempt_notifier *notifier,
+                                     struct preempt_ops *ops)
+{
+        INIT_HLIST_NODE(&notifier->link);
+        notifier->ops = ops;
+}
+
+#endif
+
 #endif /* __LINUX_PREEMPT_H */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 33b9b4841ee7..2e490271acf6 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -681,7 +681,7 @@ enum cpu_idle_type {
 #define SCHED_LOAD_SHIFT        10
 #define SCHED_LOAD_SCALE        (1L << SCHED_LOAD_SHIFT)
 
-#define SCHED_LOAD_SCALE_FUZZ   (SCHED_LOAD_SCALE >> 5)
+#define SCHED_LOAD_SCALE_FUZZ   (SCHED_LOAD_SCALE >> 1)
 
 #ifdef CONFIG_SMP
 #define SD_LOAD_BALANCE         1       /* Do load balancing on this domain. */
@@ -786,6 +786,22 @@ extern int partition_sched_domains(cpumask_t *partition1,
 
 #endif  /* CONFIG_SMP */
 
+/*
+ * A runqueue laden with a single nice 0 task scores a weighted_cpuload of
+ * SCHED_LOAD_SCALE. This function returns 1 if any cpu is laden with a
+ * task of nice 0 or enough lower priority tasks to bring up the
+ * weighted_cpuload
+ */
+static inline int above_background_load(void)
+{
+        unsigned long cpu;
+
+        for_each_online_cpu(cpu) {
+                if (weighted_cpuload(cpu) >= SCHED_LOAD_SCALE)
+                        return 1;
+        }
+        return 0;
+}
 
 struct io_context;                      /* See blkdev.h */
 struct cpuset;
@@ -935,6 +951,11 @@ struct task_struct {
         struct sched_class *sched_class;
         struct sched_entity se;
 
+#ifdef CONFIG_PREEMPT_NOTIFIERS
+        /* list of struct preempt_notifier: */
+        struct hlist_head preempt_notifiers;
+#endif
+
         unsigned short ioprio;
 #ifdef CONFIG_BLK_DEV_IO_TRACE
         unsigned int btrace_seq;