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authorOleg Nesterov <oleg@tv-sign.ru>2008-04-04 20:54:10 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-04-17 12:22:31 +0200
commit8e60e05fdc7344415fa69a3883b11f65db967b47 (patch)
treea0b13c31670221906e8d48cb7bf47dc8f8043918
parent0d180406f2914aea3a78ddb880e2fe9ac78a9372 (diff)
hrtimers: simplify lockdep handling
In order to avoid the false positive from lockdep, each per-cpu base->lock has the separate lock class and migrate_hrtimers() uses double_spin_lock(). This is overcomplicated: except for migrate_hrtimers() we never take 2 locks at once, and migrate_hrtimers() can use spin_lock_nested(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/hrtimer.h2
-rw-r--r--kernel/hrtimer.c9
2 files changed, 4 insertions, 7 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 1ad56a7b2f74..56f3236da829 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -173,7 +173,6 @@ struct hrtimer_clock_base {
* struct hrtimer_cpu_base - the per cpu clock bases
* @lock: lock protecting the base and associated clock bases
* and timers
- * @lock_key: the lock_class_key for use with lockdep
* @clock_base: array of clock bases for this cpu
* @curr_timer: the timer which is executing a callback right now
* @expires_next: absolute time of the next event which was scheduled
@@ -189,7 +188,6 @@ struct hrtimer_clock_base {
*/
struct hrtimer_cpu_base {
spinlock_t lock;
- struct lock_class_key lock_key;
struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
struct list_head cb_pending;
#ifdef CONFIG_HIGH_RES_TIMERS
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 911e87d0440d..c642ef75069f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1424,7 +1424,6 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
int i;
spin_lock_init(&cpu_base->lock);
- lockdep_set_class(&cpu_base->lock, &cpu_base->lock_key);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
cpu_base->clock_base[i].cpu_base = cpu_base;
@@ -1465,16 +1464,16 @@ static void migrate_hrtimers(int cpu)
tick_cancel_sched_timer(cpu);
local_irq_disable();
- double_spin_lock(&new_base->lock, &old_base->lock,
- smp_processor_id() < cpu);
+ spin_lock(&new_base->lock);
+ spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
migrate_hrtimer_list(&old_base->clock_base[i],
&new_base->clock_base[i]);
}
- double_spin_unlock(&new_base->lock, &old_base->lock,
- smp_processor_id() < cpu);
+ spin_unlock(&old_base->lock);
+ spin_unlock(&new_base->lock);
local_irq_enable();
put_cpu_var(hrtimer_bases);
}