performance counters: core code

[mirror_ubuntu-artful-kernel.git] / kernel / sched.c

diff --git a/kernel/sched.c b/kernel/sched.c
index 9b1e79371c207b37c1617d3f7c0460709a3cc39b..254d56de2548d11f75064127a752816eb3bcaaba 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1453,9 +1453,10 @@ static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd);
 static unsigned long cpu_avg_load_per_task(int cpu)
 {
        struct rq *rq = cpu_rq(cpu);
+       unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
 
-       if (rq->nr_running)
-               rq->avg_load_per_task = rq->load.weight / rq->nr_running;
+       if (nr_running)
+               rq->avg_load_per_task = rq->load.weight / nr_running;
        else
                rq->avg_load_per_task = 0;
 
@@ -2211,6 +2212,27 @@ static int sched_balance_self(int cpu, int flag)
 
 #endif /* CONFIG_SMP */
 
+/**
+ * task_oncpu_function_call - call a function on the cpu on which a task runs
+ * @p:         the task to evaluate
+ * @func:      the function to be called
+ * @info:      the function call argument
+ *
+ * Calls the function @func when the task is currently running. This might
+ * be on the current CPU, which just calls the function directly
+ */
+void task_oncpu_function_call(struct task_struct *p,
+                             void (*func) (void *info), void *info)
+{
+       int cpu;
+
+       preempt_disable();
+       cpu = task_cpu(p);
+       if (task_curr(p))
+               smp_call_function_single(cpu, func, info, 1);
+       preempt_enable();
+}
+
 /***
  * try_to_wake_up - wake up a thread
  * @p: the to-be-woken-up thread
@@ -2533,6 +2555,7 @@ prepare_task_switch(struct rq *rq, struct task_struct *prev,
                    struct task_struct *next)
 {
        fire_sched_out_preempt_notifiers(prev, next);
+       perf_counter_task_sched_out(prev, cpu_of(rq));
        prepare_lock_switch(rq, next);
        prepare_arch_switch(next);
 }
@@ -2573,6 +2596,7 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
         */
        prev_state = prev->state;
        finish_arch_switch(prev);
+       perf_counter_task_sched_in(current, cpu_of(rq));
        finish_lock_switch(rq, prev);
 #ifdef CONFIG_SMP
        if (current->sched_class->post_schedule)
@@ -4295,6 +4319,7 @@ void scheduler_tick(void)
        rq->idle_at_tick = idle_cpu(cpu);
        trigger_load_balance(rq, cpu);
 #endif
+       perf_counter_task_tick(curr, cpu);
 }
 
 #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \