generic, x86: add prctl commands PR_GET_TSC and PR_SET_TSC

[pandora-kernel.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 3f7c5eb..8dcdec6 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -594,18 +594,14 @@ enum {
        SCHED_FEAT_NEW_FAIR_SLEEPERS    = 1,
        SCHED_FEAT_WAKEUP_PREEMPT       = 2,
        SCHED_FEAT_START_DEBIT          = 4,
-       SCHED_FEAT_TREE_AVG             = 8,
-       SCHED_FEAT_APPROX_AVG           = 16,
-       SCHED_FEAT_HRTICK               = 32,
-       SCHED_FEAT_DOUBLE_TICK          = 64,
+       SCHED_FEAT_HRTICK               = 8,
+       SCHED_FEAT_DOUBLE_TICK          = 16,
 };
 
 const_debug unsigned int sysctl_sched_features =
                SCHED_FEAT_NEW_FAIR_SLEEPERS    * 1 |
                SCHED_FEAT_WAKEUP_PREEMPT       * 1 |
                SCHED_FEAT_START_DEBIT          * 1 |
-               SCHED_FEAT_TREE_AVG             * 0 |
-               SCHED_FEAT_APPROX_AVG           * 0 |
                SCHED_FEAT_HRTICK               * 1 |
                SCHED_FEAT_DOUBLE_TICK          * 0;
 
@@ -1056,6 +1052,49 @@ static void resched_cpu(int cpu)
        resched_task(cpu_curr(cpu));
        spin_unlock_irqrestore(&rq->lock, flags);
 }
+
+#ifdef CONFIG_NO_HZ
+/*
+ * When add_timer_on() enqueues a timer into the timer wheel of an
+ * idle CPU then this timer might expire before the next timer event
+ * which is scheduled to wake up that CPU. In case of a completely
+ * idle system the next event might even be infinite time into the
+ * future. wake_up_idle_cpu() ensures that the CPU is woken up and
+ * leaves the inner idle loop so the newly added timer is taken into
+ * account when the CPU goes back to idle and evaluates the timer
+ * wheel for the next timer event.
+ */
+void wake_up_idle_cpu(int cpu)
+{
+       struct rq *rq = cpu_rq(cpu);
+
+       if (cpu == smp_processor_id())
+               return;
+
+       /*
+        * This is safe, as this function is called with the timer
+        * wheel base lock of (cpu) held. When the CPU is on the way
+        * to idle and has not yet set rq->curr to idle then it will
+        * be serialized on the timer wheel base lock and take the new
+        * timer into account automatically.
+        */
+       if (rq->curr != rq->idle)
+               return;
+
+       /*
+        * We can set TIF_RESCHED on the idle task of the other CPU
+        * lockless. The worst case is that the other CPU runs the
+        * idle task through an additional NOOP schedule()
+        */
+       set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED);
+
+       /* NEED_RESCHED must be visible before we test polling */
+       smp_mb();
+       if (!tsk_is_polling(rq->idle))
+               smp_send_reschedule(cpu);
+}
+#endif
+
 #else
 static void __resched_task(struct task_struct *p, int tif_bit)
 {
@@ -3886,7 +3925,7 @@ need_resched_nonpreemptible:
 
        if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
                if (unlikely((prev->state & TASK_INTERRUPTIBLE) &&
-                               unlikely(signal_pending(prev)))) {
+                               signal_pending(prev))) {
                        prev->state = TASK_RUNNING;
                } else {
                        deactivate_task(rq, prev, 1);
@@ -6811,6 +6850,10 @@ static int ndoms_cur;            /* number of sched domains in 'doms_cur' */
  */
 static cpumask_t fallback_doms;
 
+void __attribute__((weak)) arch_update_cpu_topology(void)
+{
+}
+
 /*
  * Set up scheduler domains and groups. Callers must hold the hotplug lock.
  * For now this just excludes isolated cpus, but could be used to
@@ -6820,6 +6863,7 @@ static int arch_init_sched_domains(const cpumask_t *cpu_map)
 {
        int err;
 
+       arch_update_cpu_topology();
        ndoms_cur = 1;
        doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL);
        if (!doms_cur)
@@ -6924,7 +6968,7 @@ match2:
 }
 
 #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
-static int arch_reinit_sched_domains(void)
+int arch_reinit_sched_domains(void)
 {
        int err;