Commit 719254fa authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Thomas Gleixner
Browse files

NOHZ: unify the nohz function calls in irq_enter() 



We have two separate nohz function calls in irq_enter() for no good
reason. Just call a single NOHZ function from irq_enter() and call
the bits in the tick code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 2e532d68

include/linux/tick.h

+3 −4
Original line number Diff line number Diff line
@@ -96,9 +96,11 @@ extern cpumask_t *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(int cpu);

# 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) { }

# endif



#else /* CONFIG_GENERIC_CLOCKEVENTS */
@@ -106,26 +108,23 @@ 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(int cpu) { }

#endif /* !CONFIG_GENERIC_CLOCKEVENTS */



# ifdef CONFIG_NO_HZ

extern void tick_nohz_stop_sched_tick(int inidle);

extern void tick_nohz_restart_sched_tick(void);

extern void tick_nohz_update_jiffies(void);

extern ktime_t tick_nohz_get_sleep_length(void);

extern void tick_nohz_stop_idle(int cpu);

extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);

# else

static inline void tick_nohz_stop_sched_tick(int inidle) { }

static inline void tick_nohz_restart_sched_tick(void) { }

static inline void tick_nohz_update_jiffies(void) { }

static inline ktime_t tick_nohz_get_sleep_length(void)

{

	ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };



	return len;

}

static inline void tick_nohz_stop_idle(int cpu) { }

static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }

# endif /* !NO_HZ */

kernel/softirq.c

+3 −7
Original line number Diff line number Diff line
@@ -265,16 +265,12 @@ asmlinkage void do_softirq(void) 
 */

void irq_enter(void)

{

#ifdef CONFIG_NO_HZ

	int cpu = smp_processor_id();



	if (idle_cpu(cpu) && !in_interrupt())

		tick_nohz_stop_idle(cpu);

#endif

		tick_check_idle(cpu);



	__irq_enter();

#ifdef CONFIG_NO_HZ

	if (idle_cpu(cpu))

		tick_nohz_update_jiffies();

#endif

}



#ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED

kernel/time/tick-sched.c

+12 −1
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ void tick_nohz_update_jiffies(void) 
	touch_softlockup_watchdog();

}



void tick_nohz_stop_idle(int cpu)

static void tick_nohz_stop_idle(int cpu)

{

	struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
@@ -558,6 +558,17 @@ static inline void tick_nohz_switch_to_nohz(void) { } 


#endif /* NO_HZ */



/*

 * Called from irq_enter to notify about the possible interruption of idle()

 */

void tick_check_idle(int cpu)

{

#ifdef CONFIG_NO_HZ

	tick_nohz_stop_idle(cpu);

	tick_nohz_update_jiffies();

#endif

}



/*

 * High resolution timer specific code

 */