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-rw-r--r--kernel/time/tick-sched.c14
-rw-r--r--kernel/time/timekeeping.c22
2 files changed, 31 insertions, 5 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 5bbb1044f847..70f872c71f4e 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -144,7 +144,7 @@ void tick_nohz_update_jiffies(void)
if (!ts->tick_stopped)
return;
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
now = ktime_get();
ts->idle_waketime = now;
@@ -283,7 +283,7 @@ void tick_nohz_stop_sched_tick(int inidle)
if ((long)delta_jiffies >= 1) {
if (delta_jiffies > 1)
- cpu_set(cpu, nohz_cpu_mask);
+ cpumask_set_cpu(cpu, nohz_cpu_mask);
/*
* nohz_stop_sched_tick can be called several times before
* the nohz_restart_sched_tick is called. This happens when
@@ -296,7 +296,7 @@ void tick_nohz_stop_sched_tick(int inidle)
/*
* sched tick not stopped!
*/
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
goto out;
}
@@ -354,7 +354,7 @@ void tick_nohz_stop_sched_tick(int inidle)
* softirq.
*/
tick_do_update_jiffies64(ktime_get());
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
}
raise_softirq_irqoff(TIMER_SOFTIRQ);
out:
@@ -432,7 +432,7 @@ void tick_nohz_restart_sched_tick(void)
select_nohz_load_balancer(0);
now = ktime_get();
tick_do_update_jiffies64(now);
- cpu_clear(cpu, nohz_cpu_mask);
+ cpumask_clear_cpu(cpu, nohz_cpu_mask);
/*
* We stopped the tick in idle. Update process times would miss the
@@ -568,6 +568,9 @@ static void tick_nohz_switch_to_nohz(void)
*/
static void tick_nohz_kick_tick(int cpu)
{
+#if 0
+ /* Switch back to 2.6.27 behaviour */
+
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
ktime_t delta, now;
@@ -584,6 +587,7 @@ static void tick_nohz_kick_tick(int cpu)
return;
tick_nohz_restart(ts, now);
+#endif
}
#else
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e7acfb482a68..fa05e88aa76f 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -518,6 +518,28 @@ void update_wall_time(void)
/* correct the clock when NTP error is too big */
clocksource_adjust(offset);
+ /*
+ * Since in the loop above, we accumulate any amount of time
+ * in xtime_nsec over a second into xtime.tv_sec, its possible for
+ * xtime_nsec to be fairly small after the loop. Further, if we're
+ * slightly speeding the clocksource up in clocksource_adjust(),
+ * its possible the required corrective factor to xtime_nsec could
+ * cause it to underflow.
+ *
+ * Now, we cannot simply roll the accumulated second back, since
+ * the NTP subsystem has been notified via second_overflow. So
+ * instead we push xtime_nsec forward by the amount we underflowed,
+ * and add that amount into the error.
+ *
+ * We'll correct this error next time through this function, when
+ * xtime_nsec is not as small.
+ */
+ if (unlikely((s64)clock->xtime_nsec < 0)) {
+ s64 neg = -(s64)clock->xtime_nsec;
+ clock->xtime_nsec = 0;
+ clock->error += neg << (NTP_SCALE_SHIFT - clock->shift);
+ }
+
/* store full nanoseconds into xtime after rounding it up and
* add the remainder to the error difference.
*/