highres: improve debug output

Add some more debug information to the hrtimer and clock events code.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 21 insertions, 2 deletions

diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 610f44b24367..83988c3c8e22 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -524,6 +524,9 @@ void __init setup_boot_APIC_clock(void)
                  */
                 if (nmi_watchdog != NMI_IO_APIC)
                         lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+                else
+                        printk(KERN_WARNING "APIC timer registered as dummy,"
+                               " due to nmi_watchdog=1!\n");
         }
 
         /* Setup the lapic or request the broadcast */
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 72d034258ba1..065a89786628 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -558,7 +558,8 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
  */
 static int hrtimer_switch_to_hres(void)
 {
-        struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
+        int cpu = smp_processor_id();
+        struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
         unsigned long flags;
 
         if (base->hres_active)
@@ -568,6 +569,8 @@ static int hrtimer_switch_to_hres(void)
 
         if (tick_init_highres()) {
                 local_irq_restore(flags);
+                printk(KERN_WARNING "Could not switch to high resolution "
+                                    "mode on CPU %d\n", cpu);
                 return 0;
         }
         base->hres_active = 1;
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index f6997ab0c3c9..0258d3115d54 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -73,8 +73,21 @@ int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
         struct clock_event_device *dev = td->evtdev;
 
         if (!dev || !(dev->features & CLOCK_EVT_FEAT_ONESHOT) ||
-            !tick_device_is_functional(dev))
+                    !tick_device_is_functional(dev)) {
+
+                printk(KERN_INFO "Clockevents: "
+                       "could not switch to one-shot mode:");
+                if (!dev) {
+                        printk(" no tick device\n");
+                } else {
+                        if (!tick_device_is_functional(dev))
+                                printk(" %s is not functional.\n", dev->name);
+                        else
+                                printk(" %s does not support one-shot mode.\n",
+                                       dev->name);
+                }
                 return -EINVAL;
+        }
 
         td->mode = TICKDEV_MODE_ONESHOT;
         dev->event_handler = handler;