hrtimers: Convert to raw_spinlocks
Thomas Gleixner [Tue, 17 Nov 2009 15:36:54 +0000 (16:36 +0100)]
Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

include/linux/hrtimer.h
kernel/hrtimer.c
kernel/time/timer_list.c
kernel/time/timer_stats.c

index af634e9..5d86fb2 100644 (file)
@@ -169,7 +169,7 @@ struct hrtimer_clock_base {
  * @max_hang_time:     Maximum time spent in hrtimer_interrupt
  */
 struct hrtimer_cpu_base {
-       spinlock_t                      lock;
+       raw_spinlock_t                  lock;
        struct hrtimer_clock_base       clock_base[HRTIMER_MAX_CLOCK_BASES];
 #ifdef CONFIG_HIGH_RES_TIMERS
        ktime_t                         expires_next;
index d2f9239..0086628 100644 (file)
@@ -127,11 +127,11 @@ struct hrtimer_clock_base *lock_hrtimer_base(const struct hrtimer *timer,
        for (;;) {
                base = timer->base;
                if (likely(base != NULL)) {
-                       spin_lock_irqsave(&base->cpu_base->lock, *flags);
+                       raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
                        if (likely(base == timer->base))
                                return base;
                        /* The timer has migrated to another CPU: */
-                       spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
+                       raw_spin_unlock_irqrestore(&base->cpu_base->lock, *flags);
                }
                cpu_relax();
        }
@@ -208,13 +208,13 @@ again:
 
                /* See the comment in lock_timer_base() */
                timer->base = NULL;
-               spin_unlock(&base->cpu_base->lock);
-               spin_lock(&new_base->cpu_base->lock);
+               raw_spin_unlock(&base->cpu_base->lock);
+               raw_spin_lock(&new_base->cpu_base->lock);
 
                if (cpu != this_cpu && hrtimer_check_target(timer, new_base)) {
                        cpu = this_cpu;
-                       spin_unlock(&new_base->cpu_base->lock);
-                       spin_lock(&base->cpu_base->lock);
+                       raw_spin_unlock(&new_base->cpu_base->lock);
+                       raw_spin_lock(&base->cpu_base->lock);
                        timer->base = base;
                        goto again;
                }
@@ -230,7 +230,7 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 {
        struct hrtimer_clock_base *base = timer->base;
 
-       spin_lock_irqsave(&base->cpu_base->lock, *flags);
+       raw_spin_lock_irqsave(&base->cpu_base->lock, *flags);
 
        return base;
 }
@@ -628,12 +628,12 @@ static void retrigger_next_event(void *arg)
        base = &__get_cpu_var(hrtimer_bases);
 
        /* Adjust CLOCK_REALTIME offset */
-       spin_lock(&base->lock);
+       raw_spin_lock(&base->lock);
        base->clock_base[CLOCK_REALTIME].offset =
                timespec_to_ktime(realtime_offset);
 
        hrtimer_force_reprogram(base, 0);
-       spin_unlock(&base->lock);
+       raw_spin_unlock(&base->lock);
 }
 
 /*
@@ -694,9 +694,9 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 {
        if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
                if (wakeup) {
-                       spin_unlock(&base->cpu_base->lock);
+                       raw_spin_unlock(&base->cpu_base->lock);
                        raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-                       spin_lock(&base->cpu_base->lock);
+                       raw_spin_lock(&base->cpu_base->lock);
                } else
                        __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
 
@@ -790,7 +790,7 @@ static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
 static inline
 void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 {
-       spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
+       raw_spin_unlock_irqrestore(&timer->base->cpu_base->lock, *flags);
 }
 
 /**
@@ -1123,7 +1123,7 @@ ktime_t hrtimer_get_next_event(void)
        unsigned long flags;
        int i;
 
-       spin_lock_irqsave(&cpu_base->lock, flags);
+       raw_spin_lock_irqsave(&cpu_base->lock, flags);
 
        if (!hrtimer_hres_active()) {
                for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
@@ -1140,7 +1140,7 @@ ktime_t hrtimer_get_next_event(void)
                }
        }
 
-       spin_unlock_irqrestore(&cpu_base->lock, flags);
+       raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
 
        if (mindelta.tv64 < 0)
                mindelta.tv64 = 0;
@@ -1222,11 +1222,11 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
         * they get migrated to another cpu, therefore its safe to unlock
         * the timer base.
         */
-       spin_unlock(&cpu_base->lock);
+       raw_spin_unlock(&cpu_base->lock);
        trace_hrtimer_expire_entry(timer, now);
        restart = fn(timer);
        trace_hrtimer_expire_exit(timer);
-       spin_lock(&cpu_base->lock);
+       raw_spin_lock(&cpu_base->lock);
 
        /*
         * Note: We clear the CALLBACK bit after enqueue_hrtimer and
@@ -1261,7 +1261,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 retry:
        expires_next.tv64 = KTIME_MAX;
 
-       spin_lock(&cpu_base->lock);
+       raw_spin_lock(&cpu_base->lock);
        /*
         * We set expires_next to KTIME_MAX here with cpu_base->lock
         * held to prevent that a timer is enqueued in our queue via
@@ -1317,7 +1317,7 @@ retry:
         * against it.
         */
        cpu_base->expires_next = expires_next;
-       spin_unlock(&cpu_base->lock);
+       raw_spin_unlock(&cpu_base->lock);
 
        /* Reprogramming necessary ? */
        if (expires_next.tv64 == KTIME_MAX ||
@@ -1457,7 +1457,7 @@ void hrtimer_run_queues(void)
                        gettime = 0;
                }
 
-               spin_lock(&cpu_base->lock);
+               raw_spin_lock(&cpu_base->lock);
 
                while ((node = base->first)) {
                        struct hrtimer *timer;
@@ -1469,7 +1469,7 @@ void hrtimer_run_queues(void)
 
                        __run_hrtimer(timer, &base->softirq_time);
                }
-               spin_unlock(&cpu_base->lock);
+               raw_spin_unlock(&cpu_base->lock);
        }
 }
 
@@ -1625,7 +1625,7 @@ static void __cpuinit init_hrtimers_cpu(int cpu)
        struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
        int i;
 
-       spin_lock_init(&cpu_base->lock);
+       raw_spin_lock_init(&cpu_base->lock);
 
        for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
                cpu_base->clock_base[i].cpu_base = cpu_base;
@@ -1683,16 +1683,16 @@ static void migrate_hrtimers(int scpu)
         * The caller is globally serialized and nobody else
         * takes two locks at once, deadlock is not possible.
         */
-       spin_lock(&new_base->lock);
-       spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
+       raw_spin_lock(&new_base->lock);
+       raw_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]);
        }
 
-       spin_unlock(&old_base->lock);
-       spin_unlock(&new_base->lock);
+       raw_spin_unlock(&old_base->lock);
+       raw_spin_unlock(&new_base->lock);
 
        /* Check, if we got expired work to do */
        __hrtimer_peek_ahead_timers();
index 9d80db4..2826563 100644 (file)
@@ -84,7 +84,7 @@ print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
 
 next_one:
        i = 0;
-       spin_lock_irqsave(&base->cpu_base->lock, flags);
+       raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
 
        curr = base->first;
        /*
@@ -100,13 +100,13 @@ next_one:
 
                timer = rb_entry(curr, struct hrtimer, node);
                tmp = *timer;
-               spin_unlock_irqrestore(&base->cpu_base->lock, flags);
+               raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 
                print_timer(m, timer, &tmp, i, now);
                next++;
                goto next_one;
        }
-       spin_unlock_irqrestore(&base->cpu_base->lock, flags);
+       raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
 }
 
 static void
index 63b117e..2f3b585 100644 (file)
@@ -86,7 +86,7 @@ static DEFINE_SPINLOCK(table_lock);
 /*
  * Per-CPU lookup locks for fast hash lookup:
  */
-static DEFINE_PER_CPU(spinlock_t, tstats_lookup_lock);
+static DEFINE_PER_CPU(raw_spinlock_t, tstats_lookup_lock);
 
 /*
  * Mutex to serialize state changes with show-stats activities:
@@ -238,7 +238,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
        /*
         * It doesnt matter which lock we take:
         */
-       spinlock_t *lock;
+       raw_spinlock_t *lock;
        struct entry *entry, input;
        unsigned long flags;
 
@@ -253,7 +253,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
        input.pid = pid;
        input.timer_flag = timer_flag;
 
-       spin_lock_irqsave(lock, flags);
+       raw_spin_lock_irqsave(lock, flags);
        if (!timer_stats_active)
                goto out_unlock;
 
@@ -264,7 +264,7 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
                atomic_inc(&overflow_count);
 
  out_unlock:
-       spin_unlock_irqrestore(lock, flags);
+       raw_spin_unlock_irqrestore(lock, flags);
 }
 
 static void print_name_offset(struct seq_file *m, unsigned long addr)
@@ -348,10 +348,11 @@ static void sync_access(void)
        int cpu;
 
        for_each_online_cpu(cpu) {
-               spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
-               spin_lock_irqsave(lock, flags);
+               raw_spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
+
+               raw_spin_lock_irqsave(lock, flags);
                /* nothing */
-               spin_unlock_irqrestore(lock, flags);
+               raw_spin_unlock_irqrestore(lock, flags);
        }
 }
 
@@ -409,7 +410,7 @@ void __init init_timer_stats(void)
        int cpu;
 
        for_each_possible_cpu(cpu)
-               spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
+               raw_spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
 }
 
 static int __init init_tstats_procfs(void)