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authorSuresh Siddha <suresh.b.siddha@intel.com>2011-11-05 01:18:21 +0100
committerThomas Gleixner <tglx@linutronix.de>2012-02-15 15:23:09 +0100
commit77b0d60c5adf39c74039e2142a1d3cd1e4d53799 (patch)
tree9c009072825bedc6423df543b6b8e12a342cfeb7 /kernel
parentMerge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/brooni... (diff)
downloadlinux-77b0d60c5adf39c74039e2142a1d3cd1e4d53799.tar.xz
linux-77b0d60c5adf39c74039e2142a1d3cd1e4d53799.zip
clockevents: Leave the broadcast device in shutdown mode when not needed
Platforms with Always Running APIC Timer doesn't use the broadcast timer but the kernel is leaving the broadcast timer (HPET in this case) in oneshot mode. On these platforms, before the switch to oneshot mode, broadcast device is actually in shutdown mode. Code checks for empty tick_broadcast_mask and avoids going into the periodic mode. During switch to oneshot mode, add the same tick_broadcast_mask checks in the tick_broadcast_switch_to_oneshot() and avoid the broadcast device going into the oneshot mode. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: john stultz <johnstul@us.ibm.com> Cc: venki@google.com Link: http://lkml.kernel.org/r/1320452301.15071.16.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/tick-broadcast.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index fd4a7b1625a2..e883f57a3cd3 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -575,11 +575,15 @@ void tick_broadcast_switch_to_oneshot(void)
unsigned long flags;
raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
+ if (cpumask_empty(tick_get_broadcast_mask()))
+ goto end;
tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
bc = tick_broadcast_device.evtdev;
if (bc)
tick_broadcast_setup_oneshot(bc);
+
+end:
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}