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: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Martin 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>

1 files changed, 2 insertions, 555 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4376c9f3479..ae3bcaa3afb 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -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)
 {