Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt

* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt:
  clocksource: make clocksource watchdog cycle through online CPUs
  Documentation: move timer related documentation to a single place
  clockevents: optimise tick_nohz_stop_sched_tick() a bit
  locking: remove unused double_spin_lock()
  hrtimers: simplify lockdep handling
  timers: simplify lockdep handling
  posix-timers: fix shadowed variables
  timer_list: add annotations to workqueue.c
  hrtimer: use nanosleep specific restart_block fields
  hrtimer: add nanosleep specific restart_block member

14 files changed, 68 insertions, 98 deletions

diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index e8fb24671967..f7923a42e769 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -167,10 +167,8 @@ highuid.txt
         - notes on the change from 16 bit to 32 bit user/group IDs.
 hpet.txt
         - High Precision Event Timer Driver for Linux.
-hrtimer/
-        - info on the timer_stats debugging facility for timer (ab)use.
-hrtimers/
-        - info on the hrtimers subsystem for high-resolution kernel timers.
+timers/
+        - info on the timer related topics
 hw_random.txt
         - info on Linux support for random number generator in i8xx chipsets.
 hwmon/
diff --git a/Documentation/hrtimers/highres.txt b/Documentation/timers/highres.txt
index a73ecf5b4bdb..a73ecf5b4bdb 100644
--- a/Documentation/hrtimers/highres.txt
+++ b/Documentation/timers/highres.txt
diff --git a/Documentation/hrtimers/hrtimers.txt b/Documentation/timers/hrtimers.txt
index ce31f65e12e7..ce31f65e12e7 100644
--- a/Documentation/hrtimers/hrtimers.txt
+++ b/Documentation/timers/hrtimers.txt
diff --git a/Documentation/hrtimer/timer_stats.txt b/Documentation/timers/timer_stats.txt
index 20d368c59814..20d368c59814 100644
--- a/Documentation/hrtimer/timer_stats.txt
+++ b/Documentation/timers/timer_stats.txt
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/include/linux/spinlock.h b/include/linux/spinlock.h
index 1129ee0a7180..d311a090fae7 100644
--- a/include/linux/spinlock.h
+++ b/include/linux/spinlock.h
@@ -296,43 +296,6 @@ 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/include/linux/thread_info.h b/include/linux/thread_info.h
index 421323e5a2d6..accd7bad35b0 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -9,6 +9,9 @@
 
 #include <linux/types.h>
 
+struct timespec;
+struct compat_timespec;
+
 /*
  * System call restart block.
  */
@@ -26,6 +29,15 @@ struct restart_block {
                         u32 bitset;
                         u64 time;
                 } futex;
+                /* For nanosleep */
+                struct {
+                        clockid_t index;
+                        struct timespec __user *rmtp;
+#ifdef CONFIG_COMPAT
+                        struct compat_timespec __user *compat_rmtp;
+#endif
+                        u64 expires;
+                } nanosleep;
         };
 };
 
diff --git a/kernel/compat.c b/kernel/compat.c
index 5f0e201bcfd3..9c48abfcd4a5 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -47,15 +47,14 @@ static long compat_nanosleep_restart(struct restart_block *restart)
         mm_segment_t oldfs;
         long ret;
 
-        rmtp = (struct compat_timespec __user *)(restart->arg1);
-        restart->arg1 = (unsigned long)&rmt;
+        restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
         oldfs = get_fs();
         set_fs(KERNEL_DS);
         ret = hrtimer_nanosleep_restart(restart);
         set_fs(oldfs);
 
         if (ret) {
-                restart->arg1 = (unsigned long)rmtp;
+                rmtp = restart->nanosleep.compat_rmtp;
 
                 if (rmtp && put_compat_timespec(&rmt, rmtp))
                         return -EFAULT;
@@ -89,7 +88,7 @@ asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
                         = &current_thread_info()->restart_block;
 
                 restart->fn = compat_nanosleep_restart;
-                restart->arg1 = (unsigned long)rmtp;
+                restart->nanosleep.compat_rmtp = rmtp;
 
                 if (rmtp && put_compat_timespec(&rmt, rmtp))
                         return -EFAULT;
@@ -607,9 +606,9 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart)
         long err;
         mm_segment_t oldfs;
         struct timespec tu;
-        struct compat_timespec *rmtp = (struct compat_timespec *)(restart->arg1);
+        struct compat_timespec *rmtp = restart->nanosleep.compat_rmtp;
 
-        restart->arg1 = (unsigned long) &tu;
+        restart->nanosleep.rmtp = (struct timespec __user *) &tu;
         oldfs = get_fs();
         set_fs(KERNEL_DS);
         err = clock_nanosleep_restart(restart);
@@ -621,7 +620,7 @@ static long compat_clock_nanosleep_restart(struct restart_block *restart)
 
         if (err == -ERESTART_RESTARTBLOCK) {
                 restart->fn = compat_clock_nanosleep_restart;
-                restart->arg1 = (unsigned long) rmtp;
+                restart->nanosleep.compat_rmtp = rmtp;
         }
         return err;
 }
@@ -652,7 +651,7 @@ long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
         if (err == -ERESTART_RESTARTBLOCK) {
                 restart = &current_thread_info()->restart_block;
                 restart->fn = compat_clock_nanosleep_restart;
-                restart->arg1 = (unsigned long) rmtp;
+                restart->nanosleep.compat_rmtp = rmtp;
         }
         return err;
 }
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 98bee013f71f..c642ef75069f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -1354,13 +1354,13 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
         struct hrtimer_sleeper t;
         struct timespec __user  *rmtp;
 
-        hrtimer_init(&t.timer, restart->arg0, HRTIMER_MODE_ABS);
-        t.timer.expires.tv64 = ((u64)restart->arg3 << 32) | (u64) restart->arg2;
+        hrtimer_init(&t.timer, restart->nanosleep.index, HRTIMER_MODE_ABS);
+        t.timer.expires.tv64 = restart->nanosleep.expires;
 
         if (do_nanosleep(&t, HRTIMER_MODE_ABS))
                 return 0;
 
-        rmtp = (struct timespec __user *)restart->arg1;
+        rmtp = restart->nanosleep.rmtp;
         if (rmtp) {
                 int ret = update_rmtp(&t.timer, rmtp);
                 if (ret <= 0)
@@ -1394,10 +1394,9 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 
         restart = &current_thread_info()->restart_block;
         restart->fn = hrtimer_nanosleep_restart;
-        restart->arg0 = (unsigned long) t.timer.base->index;
-        restart->arg1 = (unsigned long) rmtp;
-        restart->arg2 = t.timer.expires.tv64 & 0xFFFFFFFF;
-        restart->arg3 = t.timer.expires.tv64 >> 32;
+        restart->nanosleep.index = t.timer.base->index;
+        restart->nanosleep.rmtp = rmtp;
+        restart->nanosleep.expires = t.timer.expires.tv64;
 
         return -ERESTART_RESTARTBLOCK;
 }
@@ -1425,7 +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;
@@ -1466,16 +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);
 }
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 2eae91f954ca..ae5c6c147c4b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1087,45 +1087,45 @@ static void check_process_timers(struct task_struct *tsk,
         maxfire = 20;
         prof_expires = cputime_zero;
         while (!list_empty(timers)) {
-                struct cpu_timer_list *t = list_first_entry(timers,
+                struct cpu_timer_list *tl = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(ptime, t->expires.cpu)) {
-                        prof_expires = t->expires.cpu;
+                if (!--maxfire || cputime_lt(ptime, tl->expires.cpu)) {
+                        prof_expires = tl->expires.cpu;
                         break;
                 }
-                t->firing = 1;
-                list_move_tail(&t->entry, firing);
+                tl->firing = 1;
+                list_move_tail(&tl->entry, firing);
         }
 
         ++timers;
         maxfire = 20;
         virt_expires = cputime_zero;
         while (!list_empty(timers)) {
-                struct cpu_timer_list *t = list_first_entry(timers,
+                struct cpu_timer_list *tl = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || cputime_lt(utime, t->expires.cpu)) {
-                        virt_expires = t->expires.cpu;
+                if (!--maxfire || cputime_lt(utime, tl->expires.cpu)) {
+                        virt_expires = tl->expires.cpu;
                         break;
                 }
-                t->firing = 1;
-                list_move_tail(&t->entry, firing);
+                tl->firing = 1;
+                list_move_tail(&tl->entry, firing);
         }
 
         ++timers;
         maxfire = 20;
         sched_expires = 0;
         while (!list_empty(timers)) {
-                struct cpu_timer_list *t = list_first_entry(timers,
+                struct cpu_timer_list *tl = list_first_entry(timers,
                                                       struct cpu_timer_list,
                                                       entry);
-                if (!--maxfire || sum_sched_runtime < t->expires.sched) {
-                        sched_expires = t->expires.sched;
+                if (!--maxfire || sum_sched_runtime < tl->expires.sched) {
+                        sched_expires = tl->expires.sched;
                         break;
                 }
-                t->firing = 1;
-                list_move_tail(&t->entry, firing);
+                tl->firing = 1;
+                list_move_tail(&tl->entry, firing);
         }
 
         /*
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index f61402b1f2d0..73961f35fdc8 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -141,8 +141,16 @@ static void clocksource_watchdog(unsigned long data)
         }
 
         if (!list_empty(&watchdog_list)) {
-                __mod_timer(&watchdog_timer,
-                            watchdog_timer.expires + WATCHDOG_INTERVAL);
+                /*
+                 * Cycle through CPUs to check if the CPUs stay
+                 * synchronized to each other.
+                 */
+                int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map);
+
+                if (next_cpu >= NR_CPUS)
+                        next_cpu = first_cpu(cpu_online_map);
+                watchdog_timer.expires += WATCHDOG_INTERVAL;
+                add_timer_on(&watchdog_timer, next_cpu);
         }
         spin_unlock(&watchdog_lock);
 }
@@ -164,7 +172,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                 if (!started && watchdog) {
                         watchdog_last = watchdog->read();
                         watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-                        add_timer(&watchdog_timer);
+                        add_timer_on(&watchdog_timer,
+                                     first_cpu(cpu_online_map));
                 }
         } else {
                 if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -185,7 +194,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                                 watchdog_last = watchdog->read();
                                 watchdog_timer.expires =
                                         jiffies + WATCHDOG_INTERVAL;
-                                add_timer(&watchdog_timer);
+                                add_timer_on(&watchdog_timer,
+                                             first_cpu(cpu_online_map));
                         }
                 }
         }
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 686da821d376..69dba0c71727 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -158,9 +158,8 @@ void tick_nohz_stop_idle(int cpu)
         }
 }
 
-static ktime_t tick_nohz_start_idle(int cpu)
+static ktime_t tick_nohz_start_idle(struct tick_sched *ts)
 {
-        struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
         ktime_t now, delta;
 
         now = ktime_get();
@@ -201,8 +200,8 @@ void tick_nohz_stop_sched_tick(void)
         local_irq_save(flags);
 
         cpu = smp_processor_id();
-        now = tick_nohz_start_idle(cpu);
         ts = &per_cpu(tick_cpu_sched, cpu);
+        now = tick_nohz_start_idle(ts);
 
         /*
          * If this cpu is offline and it is the one which updates
@@ -222,7 +221,6 @@ void tick_nohz_stop_sched_tick(void)
         if (need_resched())
                 goto end;
 
-        cpu = smp_processor_id();
         if (unlikely(local_softirq_pending())) {
                 static int ratelimit;
 
diff --git a/kernel/timer.c b/kernel/timer.c
index b024106daa70..f3d35d4ea42e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1228,13 +1228,6 @@ asmlinkage long sys_sysinfo(struct sysinfo __user *info)
         return 0;
 }
 
-/*
- * lockdep: we want to track each per-CPU base as a separate lock-class,
- * but timer-bases are kmalloc()-ed, so we need to attach separate
- * keys to them:
- */
-static struct lock_class_key base_lock_keys[NR_CPUS];
-
 static int __cpuinit init_timers_cpu(int cpu)
 {
         int j;
@@ -1277,7 +1270,6 @@ static int __cpuinit init_timers_cpu(int cpu)
         }
 
         spin_lock_init(&base->lock);
-        lockdep_set_class(&base->lock, base_lock_keys + cpu);
 
         for (j = 0; j < TVN_SIZE; j++) {
                 INIT_LIST_HEAD(base->tv5.vec + j);
@@ -1316,8 +1308,8 @@ static void __cpuinit migrate_timers(int cpu)
         new_base = get_cpu_var(tvec_bases);
 
         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);
 
         BUG_ON(old_base->running_timer);
 
@@ -1330,8 +1322,8 @@ static void __cpuinit migrate_timers(int cpu)
                 migrate_timer_list(new_base, old_base->tv5.vec + 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(tvec_bases);
 }
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ff06611655af..00ff4d08e370 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -219,6 +219,7 @@ int queue_delayed_work_on(int cpu, struct workqueue_struct *wq,
         struct timer_list *timer = &dwork->timer;
         struct work_struct *work = &dwork->work;
 
+        timer_stats_timer_set_start_info(&dwork->timer);
         if (!test_and_set_bit(WORK_STRUCT_PENDING, work_data_bits(work))) {
                 BUG_ON(timer_pending(timer));
                 BUG_ON(!list_empty(&work->entry));
@@ -580,6 +581,7 @@ EXPORT_SYMBOL(schedule_delayed_work);
 int schedule_delayed_work_on(int cpu,
                         struct delayed_work *dwork, unsigned long delay)
 {
+        timer_stats_timer_set_start_info(&dwork->timer);
         return queue_delayed_work_on(cpu, keventd_wq, dwork, delay);
 }
 EXPORT_SYMBOL(schedule_delayed_work_on);