X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Ftimer.c;h=fe3a9a9f832849bddbb3bf1be92268af99287aa9;hb=b5b9d6647c1cd5eee90b58941c55f874c2a7e707;hp=4f1cb0ab5251aed2b690003527a26258e15c49a0;hpb=292dd876ee765c478b27c93cc51e93a558ed58bf;p=linux-2.6

diff --git a/kernel/timer.c b/kernel/timer.c
index 4f1cb0ab52..fe3a9a9f83 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -495,7 +495,7 @@ unsigned long next_timer_interrupt(void)
 	base = &__get_cpu_var(tvec_bases);
 	spin_lock(&base->t_base.lock);
 	expires = base->timer_jiffies + (LONG_MAX >> 1);
-	list = 0;
+	list = NULL;
 
 	/* Look for timer events in tv1. */
 	j = base->timer_jiffies & TVR_MASK;
@@ -717,12 +717,16 @@ static void second_overflow(void)
 #endif
 }
 
-/* in the NTP reference this is called "hardclock()" */
-static void update_wall_time_one_tick(void)
+/*
+ * Returns how many microseconds we need to add to xtime this tick
+ * in doing an adjustment requested with adjtime.
+ */
+static long adjtime_adjustment(void)
 {
-	long time_adjust_step, delta_nsec;
+	long time_adjust_step;
 
-	if ((time_adjust_step = time_adjust) != 0 ) {
+	time_adjust_step = time_adjust;
+	if (time_adjust_step) {
 		/*
 		 * We are doing an adjtime thing.  Prepare time_adjust_step to
 		 * be within bounds.  Note that a positive time_adjust means we
@@ -733,10 +737,19 @@ static void update_wall_time_one_tick(void)
 		 */
 		time_adjust_step = min(time_adjust_step, (long)tickadj);
 		time_adjust_step = max(time_adjust_step, (long)-tickadj);
+	}
+	return time_adjust_step;
+}
 
+/* in the NTP reference this is called "hardclock()" */
+static void update_wall_time_one_tick(void)
+{
+	long time_adjust_step, delta_nsec;
+
+	time_adjust_step = adjtime_adjustment();
+	if (time_adjust_step)
 		/* Reduce by this step the amount of time left  */
 		time_adjust -= time_adjust_step;
-	}
 	delta_nsec = tick_nsec + time_adjust_step * 1000;
 	/*
 	 * Advance the phase, once it gets to one microsecond, then
@@ -758,6 +771,22 @@ static void update_wall_time_one_tick(void)
 	}
 }
 
+/*
+ * Return how long ticks are at the moment, that is, how much time
+ * update_wall_time_one_tick will add to xtime next time we call it
+ * (assuming no calls to do_adjtimex in the meantime).
+ * The return value is in fixed-point nanoseconds with SHIFT_SCALE-10
+ * bits to the right of the binary point.
+ * This function has no side-effects.
+ */
+u64 current_tick_length(void)
+{
+	long delta_nsec;
+
+	delta_nsec = tick_nsec + adjtime_adjustment() * 1000;
+	return ((u64) delta_nsec << (SHIFT_SCALE - 10)) + time_adj;
+}
+
 /*
  * Using a loop looks inefficient, but "ticks" is
  * usually just one (we shouldn't be losing ticks,