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-rw-r--r--kernel/sched/cputime.c214
1 files changed, 113 insertions, 101 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index e93cca92f38b..ea32f02bf2c3 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -115,10 +115,6 @@ static int irqtime_account_si_update(void)
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
@@ -127,19 +123,7 @@ static inline void task_group_account_field(struct task_struct *p, int index,
*/
__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
+ cpuacct_account_field(p, index, tmp);
}
/*
@@ -388,82 +372,10 @@ static inline void irqtime_account_process_tick(struct task_struct *p, int user_
struct rq *rq) {}
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-/*
- * 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 (vtime_accounting_enabled())
- return;
-
- 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 /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
-
/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- *ut = p->utime;
- *st = p->stime;
-}
-
-void thread_group_cputime_adjusted(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;
-}
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
void vtime_task_switch(struct task_struct *prev)
@@ -518,21 +430,111 @@ void vtime_account_irq_enter(struct task_struct *tsk)
}
EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ *ut = p->utime;
+ *st = p->stime;
+}
-#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
+void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ struct task_cputime cputime;
-static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
+ thread_group_cputime(p, &cputime);
+
+ *ut = cputime.utime;
+ *st = cputime.stime;
+}
+#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
+/*
+ * 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)
{
- u64 temp = (__force u64) rtime;
+ cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
+ struct rq *rq = this_rq();
- temp *= (__force u64) stime;
+ if (vtime_accounting_enabled())
+ return;
+
+ if (sched_clock_irqtime) {
+ irqtime_account_process_tick(p, user_tick, rq);
+ return;
+ }
+
+ if (steal_account_process_tick())
+ return;
- if (sizeof(cputime_t) == 4)
- temp = div_u64(temp, (__force u32) total);
+ 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
- temp = div64_u64(temp, (__force u64) total);
+ account_idle_time(cputime_one_jiffy);
+}
- return (__force cputime_t) temp;
+/*
+ * 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));
+}
+
+/*
+ * Perform (stime * rtime) / total with reduced chances
+ * of multiplication overflows by using smaller factors
+ * like quotient and remainders of divisions between
+ * rtime and total.
+ */
+static cputime_t scale_stime(u64 stime, u64 rtime, u64 total)
+{
+ u64 rem, res, scaled;
+
+ if (rtime >= total) {
+ /*
+ * Scale up to rtime / total then add
+ * the remainder scaled to stime / total.
+ */
+ res = div64_u64_rem(rtime, total, &rem);
+ scaled = stime * res;
+ scaled += div64_u64(stime * rem, total);
+ } else {
+ /*
+ * Same in reverse: scale down to total / rtime
+ * then substract that result scaled to
+ * to the remaining part.
+ */
+ res = div64_u64_rem(total, rtime, &rem);
+ scaled = div64_u64(stime, res);
+ scaled -= div64_u64(scaled * rem, total);
+ }
+
+ return (__force cputime_t) scaled;
}
/*
@@ -545,6 +547,12 @@ static void cputime_adjust(struct task_cputime *curr,
{
cputime_t rtime, stime, total;
+ if (vtime_accounting_enabled()) {
+ *ut = curr->utime;
+ *st = curr->stime;
+ return;
+ }
+
stime = curr->stime;
total = stime + curr->utime;
@@ -560,10 +568,14 @@ static void cputime_adjust(struct task_cputime *curr,
*/
rtime = nsecs_to_cputime(curr->sum_exec_runtime);
- if (total)
- stime = scale_stime(stime, rtime, total);
- else
+ if (!rtime) {
+ stime = 0;
+ } else if (!total) {
stime = rtime;
+ } else {
+ stime = scale_stime((__force u64)stime,
+ (__force u64)rtime, (__force u64)total);
+ }
/*
* If the tick based count grows faster than the scheduler one,
@@ -597,7 +609,7 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
thread_group_cputime(p, &cputime);
cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
}
-#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static unsigned long long vtime_delta(struct task_struct *tsk)