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Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/sc…
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…m/linux/kernel/git/tip/tip

Pull timer/dynticks updates from Ingo Molnar:
 "This tree contains misc dynticks updates: a fix and three cleanups"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/nohz: Fix overflow error in scheduler_tick_max_deferment()
  nohz_full: fix code style issue of tick_nohz_full_stop_tick
  nohz: Get timekeeping max deferment outside jiffies_lock
  tick: Rename tick_check_idle() to tick_irq_enter()
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torvalds committed Jan 31, 2014
2 parents 595bf99 + a2b4c60 commit aafd9d6
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Showing 5 changed files with 25 additions and 18 deletions.
6 changes: 6 additions & 0 deletions include/linux/jiffies.h
Original file line number Diff line number Diff line change
Expand Up @@ -294,6 +294,12 @@ extern unsigned long preset_lpj;
*/
extern unsigned int jiffies_to_msecs(const unsigned long j);
extern unsigned int jiffies_to_usecs(const unsigned long j);

static inline u64 jiffies_to_nsecs(const unsigned long j)
{
return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
}

extern unsigned long msecs_to_jiffies(const unsigned int m);
extern unsigned long usecs_to_jiffies(const unsigned int u);
extern unsigned long timespec_to_jiffies(const struct timespec *value);
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6 changes: 3 additions & 3 deletions include/linux/tick.h
Original file line number Diff line number Diff line change
Expand Up @@ -104,15 +104,15 @@ extern struct cpumask *tick_get_broadcast_oneshot_mask(void);
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(void);
extern void tick_irq_enter(void);
extern int tick_oneshot_mode_active(void);
# ifndef arch_needs_cpu
# define arch_needs_cpu(cpu) (0)
# endif
# 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(void) { }
static inline void tick_irq_enter(void) { }
static inline int tick_oneshot_mode_active(void) { return 0; }
# endif

Expand All @@ -121,7 +121,7 @@ static inline void tick_init(void) { }
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(void) { }
static inline void tick_irq_enter(void) { }
static inline int tick_oneshot_mode_active(void) { return 0; }
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */

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2 changes: 1 addition & 1 deletion kernel/sched/core.c
Original file line number Diff line number Diff line change
Expand Up @@ -2476,7 +2476,7 @@ u64 scheduler_tick_max_deferment(void)
if (time_before_eq(next, now))
return 0;

return jiffies_to_usecs(next - now) * NSEC_PER_USEC;
return jiffies_to_nsecs(next - now);
}
#endif

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2 changes: 1 addition & 1 deletion kernel/softirq.c
Original file line number Diff line number Diff line change
Expand Up @@ -328,7 +328,7 @@ void irq_enter(void)
* here, as softirq will be serviced on return from interrupt.
*/
local_bh_disable();
tick_check_idle();
tick_irq_enter();
_local_bh_enable();
}

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27 changes: 14 additions & 13 deletions kernel/time/tick-sched.c
Original file line number Diff line number Diff line change
Expand Up @@ -533,12 +533,13 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev;
u64 time_delta;

time_delta = timekeeping_max_deferment();

/* Read jiffies and the time when jiffies were updated last */
do {
seq = read_seqbegin(&jiffies_lock);
last_update = last_jiffies_update;
last_jiffies = jiffies;
time_delta = timekeeping_max_deferment();
} while (read_seqretry(&jiffies_lock, seq));

if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) ||
Expand Down Expand Up @@ -678,18 +679,18 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
static void tick_nohz_full_stop_tick(struct tick_sched *ts)
{
#ifdef CONFIG_NO_HZ_FULL
int cpu = smp_processor_id();
int cpu = smp_processor_id();

if (!tick_nohz_full_cpu(cpu) || is_idle_task(current))
return;
if (!tick_nohz_full_cpu(cpu) || is_idle_task(current))
return;

if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
return;
if (!ts->tick_stopped && ts->nohz_mode == NOHZ_MODE_INACTIVE)
return;

if (!can_stop_full_tick())
return;
if (!can_stop_full_tick())
return;

tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
tick_nohz_stop_sched_tick(ts, ktime_get(), cpu);
#endif
}

Expand Down Expand Up @@ -1023,7 +1024,7 @@ static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
#endif
}

static inline void tick_check_nohz_this_cpu(void)
static inline void tick_nohz_irq_enter(void)
{
struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
ktime_t now;
Expand All @@ -1042,17 +1043,17 @@ static inline void tick_check_nohz_this_cpu(void)
#else

static inline void tick_nohz_switch_to_nohz(void) { }
static inline void tick_check_nohz_this_cpu(void) { }
static inline void tick_nohz_irq_enter(void) { }

#endif /* CONFIG_NO_HZ_COMMON */

/*
* Called from irq_enter to notify about the possible interruption of idle()
*/
void tick_check_idle(void)
void tick_irq_enter(void)
{
tick_check_oneshot_broadcast_this_cpu();
tick_check_nohz_this_cpu();
tick_nohz_irq_enter();
}

/*
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