From 7372b0b122af0f6675f3ab65bfd91c8a438e0480 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 4 May 2011 15:09:27 -0700 Subject: [PATCH] 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 Cc: Dave Kleikamp Cc: Chris Mason Cc: Peter Zijlstra Cc: Tim Chen 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 --- kernel/time/tick-broadcast.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index da800ffa810c..827e0f862da4 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); } -- 2.20.1