[PATCH] hrtimer: switch sys_nanosleep to hrtimer

convert sys_nanosleep() to use hrtimer_nanosleep()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/hrtimer.c

@@ -707,6 +707,20 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 	return -ERESTART_RESTARTBLOCK;
 }
 
+asmlinkage long
+sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
+{
+	struct timespec tu;
+
+	if (copy_from_user(&tu, rqtp, sizeof(tu)))
+		return -EFAULT;
+
+	if (!timespec_valid(&tu))
+		return -EINVAL;
+
+	return hrtimer_nanosleep(&tu, rmtp, HRTIMER_REL, CLOCK_MONOTONIC);
+}
+
 /*
  * Functions related to boot-time initialization:
  */

kernel/timer.c

@@ -1120,62 +1120,6 @@ asmlinkage long sys_gettid(void)
 	return current->pid;
 }
 
-static long __sched nanosleep_restart(struct restart_block *restart)
-{
-	unsigned long expire = restart->arg0, now = jiffies;
-	struct timespec __user *rmtp = (struct timespec __user *) restart->arg1;
-	long ret;
-
-	/* Did it expire while we handled signals? */
-	if (!time_after(expire, now))
-		return 0;
-
-	expire = schedule_timeout_interruptible(expire - now);
-
-	ret = 0;
-	if (expire) {
-		struct timespec t;
-		jiffies_to_timespec(expire, &t);
-
-		ret = -ERESTART_RESTARTBLOCK;
-		if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
-			ret = -EFAULT;
-		/* The 'restart' block is already filled in */
-	}
-	return ret;
-}
-
-asmlinkage long sys_nanosleep(struct timespec __user *rqtp, struct timespec __user *rmtp)
-{
-	struct timespec t;
-	unsigned long expire;
-	long ret;
-
-	if (copy_from_user(&t, rqtp, sizeof(t)))
-		return -EFAULT;
-
-	if ((t.tv_nsec >= 1000000000L) || (t.tv_nsec < 0) || (t.tv_sec < 0))
-		return -EINVAL;
-
-	expire = timespec_to_jiffies(&t) + (t.tv_sec || t.tv_nsec);
-	expire = schedule_timeout_interruptible(expire);
-
-	ret = 0;
-	if (expire) {
-		struct restart_block *restart;
-		jiffies_to_timespec(expire, &t);
-		if (rmtp && copy_to_user(rmtp, &t, sizeof(t)))
-			return -EFAULT;
-
-		restart = &current_thread_info()->restart_block;
-		restart->fn = nanosleep_restart;
-		restart->arg0 = jiffies + expire;
-		restart->arg1 = (unsigned long) rmtp;
-		ret = -ERESTART_RESTARTBLOCK;
-	}
-	return ret;
-}
-
 /*
  * sys_sysinfo - fill in sysinfo struct
  */