summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--include/linux/hrtimer.h2
-rw-r--r--include/linux/tick.h3
-rw-r--r--kernel/hrtimer.c4
-rw-r--r--kernel/time/clocksource.c18
-rw-r--r--kernel/time/tick-oneshot.c17
5 files changed, 33 insertions, 11 deletions
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 58021b0..0d2f7c8 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -305,7 +305,7 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
extern ktime_t ktime_get(void);
extern ktime_t ktime_get_real(void);
-extern int hrtimer_hres_active(void);
+
DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
diff --git a/include/linux/tick.h b/include/linux/tick.h
index 469b82d..0482229 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -97,10 +97,12 @@ extern void tick_clock_notify(void);
extern int tick_check_oneshot_change(int allow_nohz);
extern struct tick_sched *tick_get_tick_sched(int cpu);
extern void tick_check_idle(int cpu);
+extern int tick_oneshot_mode_active(void);
# else
static inline void tick_clock_notify(void) { }
static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
static inline void tick_check_idle(int cpu) { }
+static inline int tick_oneshot_mode_active(void) { return 0; }
# endif
#else /* CONFIG_GENERIC_CLOCKEVENTS */
@@ -109,6 +111,7 @@ static inline void tick_cancel_sched_timer(int cpu) { }
static inline void tick_clock_notify(void) { }
static inline int tick_check_oneshot_change(int allow_nohz) { return 0; }
static inline void tick_check_idle(int cpu) { }
+static inline int tick_oneshot_mode_active(void) { return 0; }
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
# ifdef CONFIG_NO_HZ
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 1a70c18..cb8a15c 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -476,7 +476,7 @@ static inline int hrtimer_is_hres_enabled(void)
/*
* Is the high resolution mode active ?
*/
-int hrtimer_hres_active(void)
+static inline int hrtimer_hres_active(void)
{
return __get_cpu_var(hrtimer_bases).hres_active;
}
@@ -704,7 +704,7 @@ static int hrtimer_switch_to_hres(void)
#else
-int hrtimer_hres_active(void) { return 0; }
+static inline int hrtimer_hres_active(void) { return 0; }
static inline int hrtimer_is_hres_enabled(void) { return 0; }
static inline int hrtimer_switch_to_hres(void) { return 0; }
static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 18b9f5d..592bf58 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -30,7 +30,6 @@
#include <linux/module.h>
#include <linux/sched.h> /* for spin_unlock_irq() using preempt_count() m68k */
#include <linux/tick.h>
-#include <linux/hrtimer.h>
void timecounter_init(struct timecounter *tc,
const struct cyclecounter *cc,
@@ -511,13 +510,13 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
}
/*
- * Check to make sure we don't switch to a non-HRT usable
- * clocksource if HRT is enabled and running
+ * 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 (hrtimer_hres_active() &&
+ 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 mode\n", ovr->name);
+ "Cannot switch while in HRT/NOHZ mode\n", ovr->name);
ovr = NULL;
override_name[0] = 0;
}
@@ -550,9 +549,12 @@ sysfs_show_available_clocksources(struct sys_device *dev,
spin_lock_irq(&clocksource_lock);
list_for_each_entry(src, &clocksource_list, list) {
- /* Don't show non-HRES clocksource if HRES is enabled */
- if (!hrtimer_hres_active() ||
- (src->flags & CLOCK_SOURCE_VALID_FOR_HRES))
+ /*
+ * 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-oneshot.c b/kernel/time/tick-oneshot.c
index 2e8de67..a96c0e2 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
OpenPOWER on IntegriCloud