X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ftimer.c;h=f4152fcd9f8effecb04229c6e3a239576e7e09af;hb=75bcc8c5e1de78616b04ef9f317a293a7c1c163c;hp=f2a11887a72680605bc9af158132a4fd104fbe24;hpb=62778ba1aa2589dc78c36a32edc6f5a6ccaf50c6;p=linux-2.6

diff --git a/kernel/timer.c b/kernel/timer.c
index f2a11887a7..f4152fcd9f 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -950,6 +950,7 @@ void do_timer(struct pt_regs *regs)
 {
 	jiffies_64++;
 	update_times();
+	softlockup_tick(regs);
 }
 
 #ifdef __ARCH_WANT_SYS_ALARM
@@ -1023,7 +1024,7 @@ asmlinkage long sys_getppid(void)
 	parent = me->group_leader->real_parent;
 	for (;;) {
 		pid = parent->tgid;
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
 {
 		struct task_struct *old = parent;
 
@@ -1153,6 +1154,20 @@ fastcall signed long __sched schedule_timeout(signed long timeout)
 
 EXPORT_SYMBOL(schedule_timeout);
 
+signed long __sched schedule_timeout_interruptible(signed long timeout)
+{
+       set_current_state(TASK_INTERRUPTIBLE);
+       return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_interruptible);
+
+signed long __sched schedule_timeout_uninterruptible(signed long timeout)
+{
+       set_current_state(TASK_UNINTERRUPTIBLE);
+       return schedule_timeout(timeout);
+}
+EXPORT_SYMBOL(schedule_timeout_uninterruptible);
+
 /* Thread ID - the internal kernel "pid" */
 asmlinkage long sys_gettid(void)
 {
@@ -1169,8 +1184,7 @@ static long __sched nanosleep_restart(struct restart_block *restart)
 	if (!time_after(expire, now))
 		return 0;
 
-	current->state = TASK_INTERRUPTIBLE;
-	expire = schedule_timeout(expire - now);
+	expire = schedule_timeout_interruptible(expire - now);
 
 	ret = 0;
 	if (expire) {
@@ -1198,8 +1212,7 @@ asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __us
 		return -EINVAL;
 
 	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
-	current->state = TASK_INTERRUPTIBLE;
-	expire = schedule_timeout(expire);
+	expire = schedule_timeout_interruptible(expire);
 
 	ret = 0;
 	if (expire) {
@@ -1428,7 +1441,7 @@ static inline u64 time_interpolator_get_cycles(unsigned int src)
 	}
 }
 
-static inline u64 time_interpolator_get_counter(void)
+static inline u64 time_interpolator_get_counter(int writelock)
 {
 	unsigned int src = time_interpolator->source;
 
@@ -1442,6 +1455,15 @@ static inline u64 time_interpolator_get_counter(void)
 			now = time_interpolator_get_cycles(src);
 			if (lcycle && time_after(lcycle, now))
 				return lcycle;
+
+			/* When holding the xtime write lock, there's no need
+			 * to add the overhead of the cmpxchg.  Readers are
+			 * force to retry until the write lock is released.
+			 */
+			if (writelock) {
+				time_interpolator->last_cycle = now;
+				return now;
+			}
 			/* Keep track of the last timer value returned. The use of cmpxchg here
 			 * will cause contention in an SMP environment.
 			 */
@@ -1455,7 +1477,7 @@ static inline u64 time_interpolator_get_counter(void)
 void time_interpolator_reset(void)
 {
 	time_interpolator->offset = 0;
-	time_interpolator->last_counter = time_interpolator_get_counter();
+	time_interpolator->last_counter = time_interpolator_get_counter(1);
 }
 
 #define GET_TI_NSECS(count,i) (((((count) - i->last_counter) & (i)->mask) * (i)->nsec_per_cyc) >> (i)->shift)
@@ -1467,7 +1489,7 @@ unsigned long time_interpolator_get_offset(void)
 		return 0;
 
 	return time_interpolator->offset +
-		GET_TI_NSECS(time_interpolator_get_counter(), time_interpolator);
+		GET_TI_NSECS(time_interpolator_get_counter(0), time_interpolator);
 }
 
 #define INTERPOLATOR_ADJUST 65536
@@ -1490,7 +1512,7 @@ static void time_interpolator_update(long delta_nsec)
 	 * and the tuning logic insures that.
          */
 
-	counter = time_interpolator_get_counter();
+	counter = time_interpolator_get_counter(1);
 	offset = time_interpolator->offset + GET_TI_NSECS(counter, time_interpolator);
 
 	if (delta_nsec < 0 || (unsigned long) delta_nsec < offset)
@@ -1588,10 +1610,8 @@ void msleep(unsigned int msecs)
 {
 	unsigned long timeout = msecs_to_jiffies(msecs) + 1;
 
-	while (timeout) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		timeout = schedule_timeout(timeout);
-	}
+	while (timeout)
+		timeout = schedule_timeout_uninterruptible(timeout);
 }
 
 EXPORT_SYMBOL(msleep);
@@ -1604,10 +1624,8 @@ unsigned long msleep_interruptible(unsigned int msecs)
 {
 	unsigned long timeout = msecs_to_jiffies(msecs) + 1;
 
-	while (timeout && !signal_pending(current)) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		timeout = schedule_timeout(timeout);
-	}
+	while (timeout && !signal_pending(current))
+		timeout = schedule_timeout_interruptible(timeout);
 	return jiffies_to_msecs(timeout);
 }