tracing: user local buffer variable for trace branch tracer

[safe/jmp/linux-2.6] / kernel / time / tick-common.c

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index ab65d21..83c4417 100644 (file)
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -93,7 +93,17 @@ void tick_handle_periodic(struct clock_event_device *dev)
        for (;;) {
                if (!clockevents_program_event(dev, next, ktime_get()))
                        return;
-               tick_periodic(cpu);
+               /*
+                * Have to be careful here. If we're in oneshot mode,
+                * before we call tick_periodic() in a loop, we need
+                * to be sure we're using a real hardware clocksource.
+                * Otherwise we could get trapped in an infinite
+                * loop, as the tick_periodic() increments jiffies,
+                * when then will increment time, posibly causing
+                * the loop to trigger again and again.
+                */
+               if (timekeeping_valid_for_hres())
+                       tick_periodic(cpu);
                next = ktime_add(next, tick_period);
        }
 }
@@ -171,7 +181,7 @@ static void tick_setup_device(struct tick_device *td,
         * When the device is not per cpu, pin the interrupt to the
         * current cpu:
         */
-       if (!cpumask_equal(&newdev->cpumask, cpumask))
+       if (!cpumask_equal(newdev->cpumask, cpumask))
                irq_set_affinity(newdev->irq, cpumask);
 
        /*
@@ -202,14 +212,14 @@ static int tick_check_new_device(struct clock_event_device *newdev)
        spin_lock_irqsave(&tick_device_lock, flags);
 
        cpu = smp_processor_id();
-       if (!cpu_isset(cpu, newdev->cpumask))
+       if (!cpumask_test_cpu(cpu, newdev->cpumask))
                goto out_bc;
 
        td = &per_cpu(tick_cpu_device, cpu);
        curdev = td->evtdev;
 
        /* cpu local device ? */
-       if (!cpus_equal(newdev->cpumask, cpumask_of_cpu(cpu))) {
+       if (!cpumask_equal(newdev->cpumask, cpumask_of(cpu))) {
 
                /*
                 * If the cpu affinity of the device interrupt can not
@@ -222,7 +232,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
                 * If we have a cpu local device already, do not replace it
                 * by a non cpu local device
                 */
-               if (curdev && cpus_equal(curdev->cpumask, cpumask_of_cpu(cpu)))
+               if (curdev && cpumask_equal(curdev->cpumask, cpumask_of(cpu)))
                        goto out_bc;
        }
 
@@ -254,7 +264,7 @@ static int tick_check_new_device(struct clock_event_device *newdev)
                curdev = NULL;
        }
        clockevents_exchange_device(curdev, newdev);
-       tick_setup_device(td, newdev, cpu, &cpumask_of_cpu(cpu));
+       tick_setup_device(td, newdev, cpu, cpumask_of(cpu));
        if (newdev->features & CLOCK_EVT_FEAT_ONESHOT)
                tick_oneshot_notify();
 
@@ -274,6 +284,21 @@ out_bc:
 }
 
 /*
+ * Transfer the do_timer job away from a dying cpu.
+ *
+ * Called with interrupts disabled.
+ */
+static void tick_handover_do_timer(int *cpup)
+{
+       if (*cpup == tick_do_timer_cpu) {
+               int cpu = cpumask_first(cpu_online_mask);
+
+               tick_do_timer_cpu = (cpu < nr_cpu_ids) ? cpu :
+                       TICK_DO_TIMER_NONE;
+       }
+}
+
+/*
  * Shutdown an event device on a given cpu:
  *
  * This is called on a life CPU, when a CPU is dead. So we cannot
@@ -297,13 +322,6 @@ static void tick_shutdown(unsigned int *cpup)
                clockevents_exchange_device(dev, NULL);
                td->evtdev = NULL;
        }
-       /* Transfer the do_timer job away from this cpu */
-       if (*cpup == tick_do_timer_cpu) {
-               int cpu = first_cpu(cpu_online_map);
-
-               tick_do_timer_cpu = (cpu != NR_CPUS) ? cpu :
-                       TICK_DO_TIMER_NONE;
-       }
        spin_unlock_irqrestore(&tick_device_lock, flags);
 }
 
@@ -357,6 +375,10 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
                tick_broadcast_oneshot_control(reason);
                break;
 
+       case CLOCK_EVT_NOTIFY_CPU_DYING:
+               tick_handover_do_timer(dev);
+               break;
+
        case CLOCK_EVT_NOTIFY_CPU_DEAD:
                tick_shutdown_broadcast_oneshot(dev);
                tick_shutdown_broadcast(dev);