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Commit 73fbec60 authored by Frederic Weisbecker's avatar Frederic Weisbecker
Browse files

sched: Move cputime code to its own file 



Extract cputime code from the giant sched/core.c and
put it in its own file. This make it easier to deal with
this particular area and de-bloat a bit more core.c

Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
parent b952741c

kernel/sched/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) 
CFLAGS_core.o := $(PROFILING) -fno-omit-frame-pointer

endif



obj-y += core.o clock.o idle_task.o fair.o rt.o stop_task.o

obj-y += core.o clock.o cputime.o idle_task.o fair.o rt.o stop_task.o

obj-$(CONFIG_SMP) += cpupri.o

obj-$(CONFIG_SCHED_AUTOGROUP) += auto_group.o

obj-$(CONFIG_SCHEDSTATS) += stats.o

kernel/sched/core.c

+2 −555
Original line number Diff line number Diff line
@@ -740,126 +740,6 @@ void deactivate_task(struct rq *rq, struct task_struct *p, int flags) 
	dequeue_task(rq, p, flags);

}



#ifdef CONFIG_IRQ_TIME_ACCOUNTING



/*

 * There are no locks covering percpu hardirq/softirq time.

 * They are only modified in account_system_vtime, on corresponding CPU

 * with interrupts disabled. So, writes are safe.

 * They are read and saved off onto struct rq in update_rq_clock().

 * This may result in other CPU reading this CPU's irq time and can

 * race with irq/account_system_vtime on this CPU. We would either get old

 * or new value with a side effect of accounting a slice of irq time to wrong

 * task when irq is in progress while we read rq->clock. That is a worthy

 * compromise in place of having locks on each irq in account_system_time.

 */

static DEFINE_PER_CPU(u64, cpu_hardirq_time);

static DEFINE_PER_CPU(u64, cpu_softirq_time);



static DEFINE_PER_CPU(u64, irq_start_time);

static int sched_clock_irqtime;



void enable_sched_clock_irqtime(void)

{

	sched_clock_irqtime = 1;

}



void disable_sched_clock_irqtime(void)

{

	sched_clock_irqtime = 0;

}



#ifndef CONFIG_64BIT

static DEFINE_PER_CPU(seqcount_t, irq_time_seq);



static inline void irq_time_write_begin(void)

{

	__this_cpu_inc(irq_time_seq.sequence);

	smp_wmb();

}



static inline void irq_time_write_end(void)

{

	smp_wmb();

	__this_cpu_inc(irq_time_seq.sequence);

}



static inline u64 irq_time_read(int cpu)

{

	u64 irq_time;

	unsigned seq;



	do {

		seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));

		irq_time = per_cpu(cpu_softirq_time, cpu) +

			   per_cpu(cpu_hardirq_time, cpu);

	} while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));



	return irq_time;

}

#else /* CONFIG_64BIT */

static inline void irq_time_write_begin(void)

{

}



static inline void irq_time_write_end(void)

{

}



static inline u64 irq_time_read(int cpu)

{

	return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);

}

#endif /* CONFIG_64BIT */



/*

 * Called before incrementing preempt_count on {soft,}irq_enter

 * and before decrementing preempt_count on {soft,}irq_exit.

 */

void account_system_vtime(struct task_struct *curr)

{

	unsigned long flags;

	s64 delta;

	int cpu;



	if (!sched_clock_irqtime)

		return;



	local_irq_save(flags);



	cpu = smp_processor_id();

	delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time);

	__this_cpu_add(irq_start_time, delta);



	irq_time_write_begin();

	/*

	 * We do not account for softirq time from ksoftirqd here.

	 * We want to continue accounting softirq time to ksoftirqd thread

	 * in that case, so as not to confuse scheduler with a special task

	 * that do not consume any time, but still wants to run.

	 */

	if (hardirq_count())

		__this_cpu_add(cpu_hardirq_time, delta);

	else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())

		__this_cpu_add(cpu_softirq_time, delta);



	irq_time_write_end();

	local_irq_restore(flags);

}

EXPORT_SYMBOL_GPL(account_system_vtime);



#endif /* CONFIG_IRQ_TIME_ACCOUNTING */



#ifdef CONFIG_PARAVIRT

static inline u64 steal_ticks(u64 steal)

{

	if (unlikely(steal > NSEC_PER_SEC))

		return div_u64(steal, TICK_NSEC);



	return __iter_div_u64_rem(steal, TICK_NSEC, &steal);

}

#endif



static void update_rq_clock_task(struct rq *rq, s64 delta)

{

/*
@@ -920,43 +800,6 @@ static void update_rq_clock_task(struct rq *rq, s64 delta) 
#endif

}



#ifdef CONFIG_IRQ_TIME_ACCOUNTING

static int irqtime_account_hi_update(void)

{

	u64 *cpustat = kcpustat_this_cpu->cpustat;

	unsigned long flags;

	u64 latest_ns;

	int ret = 0;



	local_irq_save(flags);

	latest_ns = this_cpu_read(cpu_hardirq_time);

	if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_IRQ])

		ret = 1;

	local_irq_restore(flags);

	return ret;

}



static int irqtime_account_si_update(void)

{

	u64 *cpustat = kcpustat_this_cpu->cpustat;

	unsigned long flags;

	u64 latest_ns;

	int ret = 0;



	local_irq_save(flags);

	latest_ns = this_cpu_read(cpu_softirq_time);

	if (nsecs_to_cputime64(latest_ns) > cpustat[CPUTIME_SOFTIRQ])

		ret = 1;

	local_irq_restore(flags);

	return ret;

}



#else /* CONFIG_IRQ_TIME_ACCOUNTING */



#define sched_clock_irqtime	(0)



#endif



void sched_set_stop_task(int cpu, struct task_struct *stop)

{

	struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
@@ -2809,404 +2652,6 @@ unsigned long long task_sched_runtime(struct task_struct *p) 
	return ns;

}



#ifdef CONFIG_CGROUP_CPUACCT

struct cgroup_subsys cpuacct_subsys;

struct cpuacct root_cpuacct;

#endif



static inline void task_group_account_field(struct task_struct *p, int index,

					    u64 tmp)

{

#ifdef CONFIG_CGROUP_CPUACCT

	struct kernel_cpustat *kcpustat;

	struct cpuacct *ca;

#endif

	/*

	 * Since all updates are sure to touch the root cgroup, we

	 * get ourselves ahead and touch it first. If the root cgroup

	 * is the only cgroup, then nothing else should be necessary.

	 *

	 */

	__get_cpu_var(kernel_cpustat).cpustat[index] += tmp;



#ifdef CONFIG_CGROUP_CPUACCT

	if (unlikely(!cpuacct_subsys.active))

		return;



	rcu_read_lock();

	ca = task_ca(p);

	while (ca && (ca != &root_cpuacct)) {

		kcpustat = this_cpu_ptr(ca->cpustat);

		kcpustat->cpustat[index] += tmp;

		ca = parent_ca(ca);

	}

	rcu_read_unlock();

#endif

}





/*

 * Account user cpu time to a process.

 * @p: the process that the cpu time gets accounted to

 * @cputime: the cpu time spent in user space since the last update

 * @cputime_scaled: cputime scaled by cpu frequency

 */

void account_user_time(struct task_struct *p, cputime_t cputime,

		       cputime_t cputime_scaled)

{

	int index;



	/* Add user time to process. */

	p->utime += cputime;

	p->utimescaled += cputime_scaled;

	account_group_user_time(p, cputime);



	index = (TASK_NICE(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;



	/* Add user time to cpustat. */

	task_group_account_field(p, index, (__force u64) cputime);



	/* Account for user time used */

	acct_update_integrals(p);

}



/*

 * Account guest cpu time to a process.

 * @p: the process that the cpu time gets accounted to

 * @cputime: the cpu time spent in virtual machine since the last update

 * @cputime_scaled: cputime scaled by cpu frequency

 */

static void account_guest_time(struct task_struct *p, cputime_t cputime,

			       cputime_t cputime_scaled)

{

	u64 *cpustat = kcpustat_this_cpu->cpustat;



	/* Add guest time to process. */

	p->utime += cputime;

	p->utimescaled += cputime_scaled;

	account_group_user_time(p, cputime);

	p->gtime += cputime;



	/* Add guest time to cpustat. */

	if (TASK_NICE(p) > 0) {

		cpustat[CPUTIME_NICE] += (__force u64) cputime;

		cpustat[CPUTIME_GUEST_NICE] += (__force u64) cputime;

	} else {

		cpustat[CPUTIME_USER] += (__force u64) cputime;

		cpustat[CPUTIME_GUEST] += (__force u64) cputime;

	}

}



/*

 * Account system cpu time to a process and desired cpustat field

 * @p: the process that the cpu time gets accounted to

 * @cputime: the cpu time spent in kernel space since the last update

 * @cputime_scaled: cputime scaled by cpu frequency

 * @target_cputime64: pointer to cpustat field that has to be updated

 */

static inline

void __account_system_time(struct task_struct *p, cputime_t cputime,

			cputime_t cputime_scaled, int index)

{

	/* Add system time to process. */

	p->stime += cputime;

	p->stimescaled += cputime_scaled;

	account_group_system_time(p, cputime);



	/* Add system time to cpustat. */

	task_group_account_field(p, index, (__force u64) cputime);



	/* Account for system time used */

	acct_update_integrals(p);

}



/*

 * Account system cpu time to a process.

 * @p: the process that the cpu time gets accounted to

 * @hardirq_offset: the offset to subtract from hardirq_count()

 * @cputime: the cpu time spent in kernel space since the last update

 * @cputime_scaled: cputime scaled by cpu frequency

 */

void account_system_time(struct task_struct *p, int hardirq_offset,

			 cputime_t cputime, cputime_t cputime_scaled)

{

	int index;



	if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {

		account_guest_time(p, cputime, cputime_scaled);

		return;

	}



	if (hardirq_count() - hardirq_offset)

		index = CPUTIME_IRQ;

	else if (in_serving_softirq())

		index = CPUTIME_SOFTIRQ;

	else

		index = CPUTIME_SYSTEM;



	__account_system_time(p, cputime, cputime_scaled, index);

}



/*

 * Account for involuntary wait time.

 * @cputime: the cpu time spent in involuntary wait

 */

void account_steal_time(cputime_t cputime)

{

	u64 *cpustat = kcpustat_this_cpu->cpustat;



	cpustat[CPUTIME_STEAL] += (__force u64) cputime;

}



/*

 * Account for idle time.

 * @cputime: the cpu time spent in idle wait

 */

void account_idle_time(cputime_t cputime)

{

	u64 *cpustat = kcpustat_this_cpu->cpustat;

	struct rq *rq = this_rq();



	if (atomic_read(&rq->nr_iowait) > 0)

		cpustat[CPUTIME_IOWAIT] += (__force u64) cputime;

	else

		cpustat[CPUTIME_IDLE] += (__force u64) cputime;

}



static __always_inline bool steal_account_process_tick(void)

{

#ifdef CONFIG_PARAVIRT

	if (static_key_false(&paravirt_steal_enabled)) {

		u64 steal, st = 0;



		steal = paravirt_steal_clock(smp_processor_id());

		steal -= this_rq()->prev_steal_time;



		st = steal_ticks(steal);

		this_rq()->prev_steal_time += st * TICK_NSEC;



		account_steal_time(st);

		return st;

	}

#endif

	return false;

}



#ifndef CONFIG_VIRT_CPU_ACCOUNTING



#ifdef CONFIG_IRQ_TIME_ACCOUNTING

/*

 * Account a tick to a process and cpustat

 * @p: the process that the cpu time gets accounted to

 * @user_tick: is the tick from userspace

 * @rq: the pointer to rq

 *

 * Tick demultiplexing follows the order

 * - pending hardirq update

 * - pending softirq update

 * - user_time

 * - idle_time

 * - system time

 *   - check for guest_time

 *   - else account as system_time

 *

 * Check for hardirq is done both for system and user time as there is

 * no timer going off while we are on hardirq and hence we may never get an

 * opportunity to update it solely in system time.

 * p->stime and friends are only updated on system time and not on irq

 * softirq as those do not count in task exec_runtime any more.

 */

static void irqtime_account_process_tick(struct task_struct *p, int user_tick,

						struct rq *rq)

{

	cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);

	u64 *cpustat = kcpustat_this_cpu->cpustat;



	if (steal_account_process_tick())

		return;



	if (irqtime_account_hi_update()) {

		cpustat[CPUTIME_IRQ] += (__force u64) cputime_one_jiffy;

	} else if (irqtime_account_si_update()) {

		cpustat[CPUTIME_SOFTIRQ] += (__force u64) cputime_one_jiffy;

	} else if (this_cpu_ksoftirqd() == p) {

		/*

		 * ksoftirqd time do not get accounted in cpu_softirq_time.

		 * So, we have to handle it separately here.

		 * Also, p->stime needs to be updated for ksoftirqd.

		 */

		__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,

					CPUTIME_SOFTIRQ);

	} else if (user_tick) {

		account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);

	} else if (p == rq->idle) {

		account_idle_time(cputime_one_jiffy);

	} else if (p->flags & PF_VCPU) { /* System time or guest time */

		account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled);

	} else {

		__account_system_time(p, cputime_one_jiffy, one_jiffy_scaled,

					CPUTIME_SYSTEM);

	}

}



static void irqtime_account_idle_ticks(int ticks)

{

	int i;

	struct rq *rq = this_rq();



	for (i = 0; i < ticks; i++)

		irqtime_account_process_tick(current, 0, rq);

}

#else /* CONFIG_IRQ_TIME_ACCOUNTING */

static void irqtime_account_idle_ticks(int ticks) {}

static void irqtime_account_process_tick(struct task_struct *p, int user_tick,

						struct rq *rq) {}

#endif /* CONFIG_IRQ_TIME_ACCOUNTING */



/*

 * Account a single tick of cpu time.

 * @p: the process that the cpu time gets accounted to

 * @user_tick: indicates if the tick is a user or a system tick

 */

void account_process_tick(struct task_struct *p, int user_tick)

{

	cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);

	struct rq *rq = this_rq();



	if (sched_clock_irqtime) {

		irqtime_account_process_tick(p, user_tick, rq);

		return;

	}



	if (steal_account_process_tick())

		return;



	if (user_tick)

		account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);

	else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))

		account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,

				    one_jiffy_scaled);

	else

		account_idle_time(cputime_one_jiffy);

}



/*

 * Account multiple ticks of steal time.

 * @p: the process from which the cpu time has been stolen

 * @ticks: number of stolen ticks

 */

void account_steal_ticks(unsigned long ticks)

{

	account_steal_time(jiffies_to_cputime(ticks));

}



/*

 * Account multiple ticks of idle time.

 * @ticks: number of stolen ticks

 */

void account_idle_ticks(unsigned long ticks)

{



	if (sched_clock_irqtime) {

		irqtime_account_idle_ticks(ticks);

		return;

	}



	account_idle_time(jiffies_to_cputime(ticks));

}



#endif



/*

 * Use precise platform statistics if available:

 */

#ifdef CONFIG_VIRT_CPU_ACCOUNTING

void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)

{

	*ut = p->utime;

	*st = p->stime;

}



void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)

{

	struct task_cputime cputime;



	thread_group_cputime(p, &cputime);



	*ut = cputime.utime;

	*st = cputime.stime;

}

#else



#ifndef nsecs_to_cputime

# define nsecs_to_cputime(__nsecs)	nsecs_to_jiffies(__nsecs)

#endif



static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)

{

	u64 temp = (__force u64) rtime;



	temp *= (__force u64) utime;



	if (sizeof(cputime_t) == 4)

		temp = div_u64(temp, (__force u32) total);

	else

		temp = div64_u64(temp, (__force u64) total);



	return (__force cputime_t) temp;

}



void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)

{

	cputime_t rtime, utime = p->utime, total = utime + p->stime;



	/*

	 * Use CFS's precise accounting:

	 */

	rtime = nsecs_to_cputime(p->se.sum_exec_runtime);



	if (total)

		utime = scale_utime(utime, rtime, total);

	else

		utime = rtime;



	/*

	 * Compare with previous values, to keep monotonicity:

	 */

	p->prev_utime = max(p->prev_utime, utime);

	p->prev_stime = max(p->prev_stime, rtime - p->prev_utime);



	*ut = p->prev_utime;

	*st = p->prev_stime;

}



/*

 * Must be called with siglock held.

 */

void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)

{

	struct signal_struct *sig = p->signal;

	struct task_cputime cputime;

	cputime_t rtime, utime, total;



	thread_group_cputime(p, &cputime);



	total = cputime.utime + cputime.stime;

	rtime = nsecs_to_cputime(cputime.sum_exec_runtime);



	if (total)

		utime = scale_utime(cputime.utime, rtime, total);

	else

		utime = rtime;



	sig->prev_utime = max(sig->prev_utime, utime);

	sig->prev_stime = max(sig->prev_stime, rtime - sig->prev_utime);



	*ut = sig->prev_utime;

	*st = sig->prev_stime;

}

#endif



/*

 * This function gets called by the timer code, with HZ frequency.

 * We call it with interrupts disabled.
@@ -8419,6 +7864,8 @@ struct cgroup_subsys cpu_cgroup_subsys = { 
 * (balbir@in.ibm.com).

 */



struct cpuacct root_cpuacct;



/* create a new cpu accounting group */

static struct cgroup_subsys_state *cpuacct_create(struct cgroup *cgrp)

{

kernel/sched/cputime.c

0 → 100644
+504 −0

File added.

Preview size limit exceeded, changes collapsed.

kernel/sched/sched.h

+63 −0
Original line number Diff line number Diff line
@@ -891,6 +891,9 @@ struct cpuacct { 
	struct kernel_cpustat __percpu *cpustat;

};



extern struct cgroup_subsys cpuacct_subsys;

extern struct cpuacct root_cpuacct;



/* return cpu accounting group corresponding to this container */

static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)

{
@@ -917,6 +920,16 @@ extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); 
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}

#endif



#ifdef CONFIG_PARAVIRT

static inline u64 steal_ticks(u64 steal)

{

	if (unlikely(steal > NSEC_PER_SEC))

		return div_u64(steal, TICK_NSEC);



	return __iter_div_u64_rem(steal, TICK_NSEC, &steal);

}

#endif



static inline void inc_nr_running(struct rq *rq)

{

	rq->nr_running++;
@@ -1157,3 +1170,53 @@ enum rq_nohz_flag_bits { 


#define nohz_flags(cpu)	(&cpu_rq(cpu)->nohz_flags)

#endif



#ifdef CONFIG_IRQ_TIME_ACCOUNTING



DECLARE_PER_CPU(u64, cpu_hardirq_time);

DECLARE_PER_CPU(u64, cpu_softirq_time);



#ifndef CONFIG_64BIT

DECLARE_PER_CPU(seqcount_t, irq_time_seq);



static inline void irq_time_write_begin(void)

{

	__this_cpu_inc(irq_time_seq.sequence);

	smp_wmb();

}



static inline void irq_time_write_end(void)

{

	smp_wmb();

	__this_cpu_inc(irq_time_seq.sequence);

}



static inline u64 irq_time_read(int cpu)

{

	u64 irq_time;

	unsigned seq;



	do {

		seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));

		irq_time = per_cpu(cpu_softirq_time, cpu) +

			   per_cpu(cpu_hardirq_time, cpu);

	} while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));



	return irq_time;

}

#else /* CONFIG_64BIT */

static inline void irq_time_write_begin(void)

{

}



static inline void irq_time_write_end(void)

{

}



static inline u64 irq_time_read(int cpu)

{

	return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);

}

#endif /* CONFIG_64BIT */

#endif /* CONFIG_IRQ_TIME_ACCOUNTING */