Commit a554a25e authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Rafael J. Wysocki
Browse files

cpufreq: ondemand: Simplify idle cputime granularity test 



cpufreq calls get_cpu_idle_time_us() just to know if idle cputime
accounting has a nanoseconds granularity.

Use the appropriate indicator instead to make that deduction.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Link: https://patch.msgid.link/aXozx0PXutnm8ECX@localhost.localdomain


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent cc764d3b

drivers/cpufreq/cpufreq_ondemand.c

+1 −6
Original line number Diff line number Diff line
@@ -334,17 +334,12 @@ static void od_free(struct policy_dbs_info *policy_dbs) 
static int od_init(struct dbs_data *dbs_data)

{

	struct od_dbs_tuners *tuners;

	u64 idle_time;

	int cpu;



	tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);

	if (!tuners)

		return -ENOMEM;



	cpu = get_cpu();

	idle_time = get_cpu_idle_time_us(cpu, NULL);

	put_cpu();

	if (idle_time != -1ULL) {

	if (tick_nohz_is_active()) {

		/* Idle micro accounting is supported. Use finer thresholds */

		dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;

	} else {

include/linux/tick.h

+2 −0
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ enum tick_dep_bits { 


#ifdef CONFIG_NO_HZ_COMMON

extern bool tick_nohz_enabled;

extern bool tick_nohz_is_active(void);

extern bool tick_nohz_tick_stopped(void);

extern bool tick_nohz_tick_stopped_cpu(int cpu);

extern void tick_nohz_idle_stop_tick(void);
@@ -142,6 +143,7 @@ extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); 
extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);

#else /* !CONFIG_NO_HZ_COMMON */

#define tick_nohz_enabled (0)

static inline bool tick_nohz_is_active(void) { return false; }

static inline int tick_nohz_tick_stopped(void) { return 0; }

static inline int tick_nohz_tick_stopped_cpu(int cpu) { return 0; }

static inline void tick_nohz_idle_stop_tick(void) { }

kernel/time/hrtimer.c

+1 −1
Original line number Diff line number Diff line
@@ -943,7 +943,7 @@ void clock_was_set(unsigned int bases) 
	cpumask_var_t mask;

	int cpu;



	if (!hrtimer_hres_active(cpu_base) && !tick_nohz_active)

	if (!hrtimer_hres_active(cpu_base) && !tick_nohz_is_active())

		goto out_timerfd;



	if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) {

kernel/time/tick-internal.h

+0 −2
Original line number Diff line number Diff line
@@ -156,7 +156,6 @@ static inline void tick_nohz_init(void) { } 
#endif



#ifdef CONFIG_NO_HZ_COMMON

extern unsigned long tick_nohz_active;

extern void timers_update_nohz(void);

extern u64 get_jiffies_update(unsigned long *basej);

# ifdef CONFIG_SMP
@@ -171,7 +170,6 @@ extern void timer_expire_remote(unsigned int cpu); 
# endif

#else /* CONFIG_NO_HZ_COMMON */

static inline void timers_update_nohz(void) { }

#define tick_nohz_active (0)

#endif



DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);

kernel/time/tick-sched.c

+7 −1
Original line number Diff line number Diff line
@@ -693,7 +693,7 @@ void __init tick_nohz_init(void) 
 * NO HZ enabled ?

 */

bool tick_nohz_enabled __read_mostly  = true;

unsigned long tick_nohz_active  __read_mostly;

static unsigned long tick_nohz_active  __read_mostly;

/*

 * Enable / Disable tickless mode

 */
@@ -704,6 +704,12 @@ static int __init setup_tick_nohz(char *str) 


__setup("nohz=", setup_tick_nohz);



bool tick_nohz_is_active(void)

{

	return tick_nohz_active;

}

EXPORT_SYMBOL_GPL(tick_nohz_is_active);



bool tick_nohz_tick_stopped(void)

{

	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);