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-rw-r--r--kernel/time/clockevents.c2
-rw-r--r--kernel/time/clocksource.c23
-rw-r--r--kernel/time/tick-broadcast.c2
-rw-r--r--kernel/time/tick-common.c12
-rw-r--r--kernel/time/tick-oneshot.c17
-rw-r--r--kernel/time/timekeeping.c9
6 files changed, 58 insertions, 7 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index ab20ded013bd..1ad6dd461119 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -55,6 +55,7 @@ unsigned long clockevent_delta2ns(unsigned long latch,
return (unsigned long) clc;
}
+EXPORT_SYMBOL_GPL(clockevent_delta2ns);
/**
* clockevents_set_mode - set the operating mode of a clock event device
@@ -188,6 +189,7 @@ void clockevents_register_device(struct clock_event_device *dev)
spin_unlock(&clockevents_lock);
}
+EXPORT_SYMBOL_GPL(clockevents_register_device);
/*
* Noop handler when we shut down an event device
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index ecfd7b5187e0..592bf584d1d2 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -402,9 +402,6 @@ int clocksource_register(struct clocksource *c)
unsigned long flags;
int ret;
- /* save mult_orig on registration */
- c->mult_orig = c->mult;
-
spin_lock_irqsave(&clocksource_lock, flags);
ret = clocksource_enqueue(c);
if (!ret)
@@ -512,6 +509,18 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
}
}
+ /*
+ * Check to make sure we don't switch to a non-highres capable
+ * clocksource if the tick code is in oneshot mode (highres or nohz)
+ */
+ if (tick_oneshot_mode_active() &&
+ !(ovr->flags & CLOCK_SOURCE_VALID_FOR_HRES)) {
+ printk(KERN_WARNING "%s clocksource is not HRT compatible. "
+ "Cannot switch while in HRT/NOHZ mode\n", ovr->name);
+ ovr = NULL;
+ override_name[0] = 0;
+ }
+
/* Reselect, when the override name has changed */
if (ovr != clocksource_override) {
clocksource_override = ovr;
@@ -540,7 +549,13 @@ sysfs_show_available_clocksources(struct sys_device *dev,
spin_lock_irq(&clocksource_lock);
list_for_each_entry(src, &clocksource_list, list) {
- count += snprintf(buf + count,
+ /*
+ * Don't show non-HRES clocksource if the tick code is
+ * in one shot mode (highres=on or nohz=on)
+ */
+ if (!tick_oneshot_mode_active() ||
+ (src->flags & CLOCK_SOURCE_VALID_FOR_HRES))
+ count += snprintf(buf + count,
max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
"%s ", src->name);
}
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 118a3b3b3f9a..877dbedc3118 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -27,7 +27,7 @@
* timer stops in C3 state.
*/
-struct tick_device tick_broadcast_device;
+static struct tick_device tick_broadcast_device;
/* FIXME: Use cpumask_var_t. */
static DECLARE_BITMAP(tick_broadcast_mask, NR_CPUS);
static DECLARE_BITMAP(tmpmask, NR_CPUS);
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 21a5ca849514..83c4417b6a3c 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -93,7 +93,17 @@ void tick_handle_periodic(struct clock_event_device *dev)
for (;;) {
if (!clockevents_program_event(dev, next, ktime_get()))
return;
- tick_periodic(cpu);
+ /*
+ * Have to be careful here. If we're in oneshot mode,
+ * before we call tick_periodic() in a loop, we need
+ * to be sure we're using a real hardware clocksource.
+ * Otherwise we could get trapped in an infinite
+ * loop, as the tick_periodic() increments jiffies,
+ * when then will increment time, posibly causing
+ * the loop to trigger again and again.
+ */
+ if (timekeeping_valid_for_hres())
+ tick_periodic(cpu);
next = ktime_add(next, tick_period);
}
}
diff --git a/kernel/time/tick-oneshot.c b/kernel/time/tick-oneshot.c
index 2e8de678e767..a96c0e2b89cf 100644
--- a/kernel/time/tick-oneshot.c
+++ b/kernel/time/tick-oneshot.c
@@ -128,6 +128,23 @@ int tick_switch_to_oneshot(void (*handler)(struct clock_event_device *))
return 0;
}
+/**
+ * tick_check_oneshot_mode - check whether the system is in oneshot mode
+ *
+ * returns 1 when either nohz or highres are enabled. otherwise 0.
+ */
+int tick_oneshot_mode_active(void)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+ ret = __get_cpu_var(tick_cpu_device).mode == TICKDEV_MODE_ONESHOT;
+ local_irq_restore(flags);
+
+ return ret;
+}
+
#ifdef CONFIG_HIGH_RES_TIMERS
/**
* tick_init_highres - switch to high resolution mode
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 687dff49f6e7..e8c77d9c633a 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -22,7 +22,7 @@
/*
* This read-write spinlock protects us from races in SMP while
- * playing with xtime and avenrun.
+ * playing with xtime.
*/
__cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
@@ -77,6 +77,10 @@ static void clocksource_forward_now(void)
clock->cycle_last = cycle_now;
nsec = cyc2ns(clock, cycle_delta);
+
+ /* If arch requires, add in gettimeoffset() */
+ nsec += arch_gettimeoffset();
+
timespec_add_ns(&xtime, nsec);
nsec = ((s64)cycle_delta * clock->mult_orig) >> clock->shift;
@@ -111,6 +115,9 @@ void getnstimeofday(struct timespec *ts)
/* convert to nanoseconds: */
nsecs = cyc2ns(clock, cycle_delta);
+ /* If arch requires, add in gettimeoffset() */
+ nsecs += arch_gettimeoffset();
+
} while (read_seqretry(&xtime_lock, seq));
timespec_add_ns(ts, nsecs);