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authorAndi Kleen <ak@linux.intel.com>2011-05-04 15:09:27 -0700
committerThomas Gleixner <tglx@linutronix.de>2011-05-05 17:32:13 +0200
commit7372b0b122af0f6675f3ab65bfd91c8a438e0480 (patch)
tree5dcd0f94e0064b76573837da09ca5277b7e5f068
parent179eb03268aa1da03d90f1566ea85dc1478d3ae3 (diff)
downloadop-kernel-dev-7372b0b122af0f6675f3ab65bfd91c8a438e0480.zip
op-kernel-dev-7372b0b122af0f6675f3ab65bfd91c8a438e0480.tar.gz
clockevents: Move C3 stop test outside lock
Avoid taking broadcast_lock in the idle path for systems where the timer doesn't stop in C3. [ tglx: Removed the stale label and added comment ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Dave Kleikamp <dkleikamp@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: lenb@kernel.org Cc: paulmck@us.ibm.com Link: http://lkml.kernel.org/r/%3C20110504234806.GF2925%40one.firstfloor.org%3E Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/time/tick-broadcast.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index da800ff..827e0f8 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -456,23 +456,27 @@ void tick_broadcast_oneshot_control(unsigned long reason)
unsigned long flags;
int cpu;
- raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-
/*
* Periodic mode does not care about the enter/exit of power
* states
*/
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
- goto out;
+ return;
- bc = tick_broadcast_device.evtdev;
+ /*
+ * We are called with preemtion disabled from the depth of the
+ * idle code, so we can't be moved away.
+ */
cpu = smp_processor_id();
td = &per_cpu(tick_cpu_device, cpu);
dev = td->evtdev;
if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
- goto out;
+ return;
+
+ bc = tick_broadcast_device.evtdev;
+ raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask());
@@ -489,8 +493,6 @@ void tick_broadcast_oneshot_control(unsigned long reason)
tick_program_event(dev->next_event, 1);
}
}
-
-out:
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}
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