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-rw-r--r--include/linux/spinlock.h37
-rw-r--r--kernel/hrtimer.c9
-rw-r--r--kernel/timer.c8
3 files changed, 45 insertions, 9 deletions
diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
index 61fef376ed2..a946176db63 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -283,6 +283,43 @@ do { \
})
/*
+ * Locks two spinlocks l1 and l2.
+ * l1_first indicates if spinlock l1 should be taken first.
+ */
+static inline void double_spin_lock(spinlock_t *l1, spinlock_t *l2,
+ bool l1_first)
+ __acquires(l1)
+ __acquires(l2)
+{
+ if (l1_first) {
+ spin_lock(l1);
+ spin_lock(l2);
+ } else {
+ spin_lock(l2);
+ spin_lock(l1);
+ }
+}
+
+/*
+ * Unlocks two spinlocks l1 and l2.
+ * l1_taken_first indicates if spinlock l1 was taken first and therefore
+ * should be released after spinlock l2.
+ */
+static inline void double_spin_unlock(spinlock_t *l1, spinlock_t *l2,
+ bool l1_taken_first)
+ __releases(l1)
+ __releases(l2)
+{
+ if (l1_taken_first) {
+ spin_unlock(l2);
+ spin_unlock(l1);
+ } else {
+ spin_unlock(l1);
+ spin_unlock(l2);
+ }
+}
+
+/*
* Pull the atomic_t declaration:
* (asm-mips/atomic.h needs above definitions)
*/
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 476cb0c0b4a..de93a8176ca 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1355,17 +1355,16 @@ static void migrate_hrtimers(int cpu)
tick_cancel_sched_timer(cpu);
local_irq_disable();
-
- spin_lock(&new_base->lock);
- spin_lock(&old_base->lock);
+ double_spin_lock(&new_base->lock, &old_base->lock,
+ smp_processor_id() < cpu);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
migrate_hrtimer_list(&old_base->clock_base[i],
&new_base->clock_base[i]);
}
- spin_unlock(&old_base->lock);
- spin_unlock(&new_base->lock);
+ double_spin_unlock(&new_base->lock, &old_base->lock,
+ smp_processor_id() < cpu);
local_irq_enable();
put_cpu_var(hrtimer_bases);
}
diff --git a/kernel/timer.c b/kernel/timer.c
index 6663a87f730..8ad384253ef 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1651,8 +1651,8 @@ static void __devinit migrate_timers(int cpu)
new_base = get_cpu_var(tvec_bases);
local_irq_disable();
- spin_lock(&new_base->lock);
- spin_lock(&old_base->lock);
+ double_spin_lock(&new_base->lock, &old_base->lock,
+ smp_processor_id() < cpu);
BUG_ON(old_base->running_timer);
@@ -1665,8 +1665,8 @@ static void __devinit migrate_timers(int cpu)
migrate_timer_list(new_base, old_base->tv5.vec + i);
}
- spin_unlock(&old_base->lock);
- spin_unlock(&new_base->lock);
+ double_spin_unlock(&new_base->lock, &old_base->lock,
+ smp_processor_id() < cpu);
local_irq_enable();
put_cpu_var(tvec_bases);
}