3 files changed, 69 insertions, 37 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 5b03679ff712..635eaffe1e4c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4139,7 +4139,6 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
                          cputime_t cputime, cputime_t cputime_scaled)
 {
         struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-        struct rq *rq = this_rq();
         cputime64_t tmp;
 
         if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
@@ -4158,37 +4157,84 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
                 cpustat->irq = cputime64_add(cpustat->irq, tmp);
         else if (softirq_count())
                 cpustat->softirq = cputime64_add(cpustat->softirq, tmp);
-        else if (p != rq->idle)
-                cpustat->system = cputime64_add(cpustat->system, tmp);
-        else if (atomic_read(&rq->nr_iowait) > 0)
-                cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
         else
-                cpustat->idle = cputime64_add(cpustat->idle, tmp);
+                cpustat->system = cputime64_add(cpustat->system, tmp);
+
         /* Account for system time used */
         acct_update_integrals(p);
 }
 
 /*
  * Account for involuntary wait time.
- * @p: the process from which the cpu time has been stolen
  * @steal: the cpu time spent in involuntary wait
  */
-void account_steal_time(struct task_struct *p, cputime_t steal)
+void account_steal_time(cputime_t cputime)
+{
+        struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
+        cputime64_t cputime64 = cputime_to_cputime64(cputime);
+
+        cpustat->steal = cputime64_add(cpustat->steal, cputime64);
+}
+
+/*
+ * Account for idle time.
+ * @cputime: the cpu time spent in idle wait
+ */
+void account_idle_time(cputime_t cputime)
 {
         struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
-        cputime64_t tmp = cputime_to_cputime64(steal);
+        cputime64_t cputime64 = cputime_to_cputime64(cputime);
         struct rq *rq = this_rq();
 
-        if (p == rq->idle) {
-                p->stime = cputime_add(p->stime, steal);
-                if (atomic_read(&rq->nr_iowait) > 0)
-                        cpustat->iowait = cputime64_add(cpustat->iowait, tmp);
-                else
-                        cpustat->idle = cputime64_add(cpustat->idle, tmp);
-        } else
-                cpustat->steal = cputime64_add(cpustat->steal, tmp);
+        if (atomic_read(&rq->nr_iowait) > 0)
+                cpustat->iowait = cputime64_add(cpustat->iowait, cputime64);
+        else
+                cpustat->idle = cputime64_add(cpustat->idle, cputime64);
+}
+
+#ifndef CONFIG_VIRT_CPU_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 = jiffies_to_cputime(1);
+        cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy);
+        struct rq *rq = this_rq();
+
+        if (user_tick)
+                account_user_time(p, one_jiffy, one_jiffy_scaled);
+        else if (p != rq->idle)
+                account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
+                                    one_jiffy_scaled);
+        else
+                account_idle_time(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)
+{
+        account_idle_time(jiffies_to_cputime(ticks));
 }
 
+#endif
+
 /*
  * Use precise platform statistics if available:
  */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 1f2fce2479fe..611fa4c0baab 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -419,8 +419,9 @@ void tick_nohz_restart_sched_tick(void)
 {
         int cpu = smp_processor_id();
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
         unsigned long ticks;
-        cputime_t cputime;
+#endif
         ktime_t now;
 
         local_irq_disable();
@@ -442,6 +443,7 @@ void tick_nohz_restart_sched_tick(void)
         tick_do_update_jiffies64(now);
         cpu_clear(cpu, nohz_cpu_mask);
 
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
         /*
          * We stopped the tick in idle. Update process times would miss the
          * time we slept as update_process_times does only a 1 tick
@@ -451,12 +453,9 @@ void tick_nohz_restart_sched_tick(void)
         /*
          * We might be one off. Do not randomly account a huge number of ticks!
          */
-        if (ticks && ticks < LONG_MAX) {
-                add_preempt_count(HARDIRQ_OFFSET);
-                cputime = jiffies_to_cputime(ticks);
-                account_system_time(current, HARDIRQ_OFFSET, cputime, cputime);
-                sub_preempt_count(HARDIRQ_OFFSET);
-        }
+        if (ticks && ticks < LONG_MAX)
+                account_idle_ticks(ticks);
+#endif
 
         touch_softlockup_watchdog();
         /*
diff --git a/kernel/timer.c b/kernel/timer.c
index b5efb528aa1d..dee3f641a7a7 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1018,19 +1018,6 @@ unsigned long get_next_timer_interrupt(unsigned long now)
 }
 #endif
 
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
-void account_process_tick(struct task_struct *p, int user_tick)
-{
-        cputime_t one_jiffy = jiffies_to_cputime(1);
-
-        if (user_tick)
-                account_user_time(p, one_jiffy, cputime_to_scaled(one_jiffy));
-        else
-                account_system_time(p, HARDIRQ_OFFSET, one_jiffy,
-                                    cputime_to_scaled(one_jiffy));
-}
-#endif
-
 /*
  * Called from the timer interrupt handler to charge one tick to the current
  * process.  user_tick is 1 if the tick is user time, 0 for system.