1 files changed, 104 insertions, 5 deletions

diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 8385d43987e2..3b01098164c8 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -9,7 +9,7 @@
 static int show_schedstat(struct seq_file *seq, void *v)
 {
         int cpu;
-        int mask_len = NR_CPUS/32 * 9;
+        int mask_len = DIV_ROUND_UP(NR_CPUS, 32) * 9;
         char *mask_str = kmalloc(mask_len, GFP_KERNEL);
 
         if (mask_str == NULL)
@@ -31,7 +31,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
                     rq->yld_act_empty, rq->yld_exp_empty, rq->yld_count,
                     rq->sched_switch, rq->sched_count, rq->sched_goidle,
                     rq->ttwu_count, rq->ttwu_local,
-                    rq->rq_sched_info.cpu_time,
+                    rq->rq_cpu_time,
                     rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
 
                 seq_printf(seq, "\n");
@@ -90,13 +90,20 @@ static int schedstat_open(struct inode *inode, struct file *file)
         return res;
 }
 
-const struct file_operations proc_schedstat_operations = {
+static const struct file_operations proc_schedstat_operations = {
         .open    = schedstat_open,
         .read    = seq_read,
         .llseek  = seq_lseek,
         .release = single_release,
 };
 
+static int __init proc_schedstat_init(void)
+{
+        proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
+        return 0;
+}
+module_init(proc_schedstat_init);
+
 /*
  * Expects runqueue lock to be held for atomicity of update
  */
@@ -116,7 +123,7 @@ static inline void
 rq_sched_info_depart(struct rq *rq, unsigned long long delta)
 {
         if (rq)
-                rq->rq_sched_info.cpu_time += delta;
+                rq->rq_cpu_time += delta;
 }
 
 static inline void
@@ -229,7 +236,6 @@ static inline void sched_info_depart(struct task_struct *t)
         unsigned long long delta = task_rq(t)->clock -
                                         t->sched_info.last_arrival;
 
-        t->sched_info.cpu_time += delta;
         rq_sched_info_depart(task_rq(t), delta);
 
         if (t->state == TASK_RUNNING)
@@ -270,3 +276,96 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next)
 #define sched_info_switch(t, next)              do { } while (0)
 #endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */
 
+/*
+ * The following are functions that support scheduler-internal time accounting.
+ * These functions are generally called at the timer tick.  None of this depends
+ * on CONFIG_SCHEDSTATS.
+ */
+
+/**
+ * account_group_user_time - Maintain utime for a thread group.
+ *
+ * @tsk:        Pointer to task structure.
+ * @cputime:    Time value by which to increment the utime field of the
+ *              thread_group_cputime structure.
+ *
+ * If thread group time is being maintained, get the structure for the
+ * running CPU and update the utime field there.
+ */
+static inline void account_group_user_time(struct task_struct *tsk,
+                                           cputime_t cputime)
+{
+        struct signal_struct *sig;
+
+        /* tsk == current, ensure it is safe to use ->signal */
+        if (unlikely(tsk->exit_state))
+                return;
+
+        sig = tsk->signal;
+        if (sig->cputime.totals) {
+                struct task_cputime *times;
+
+                times = per_cpu_ptr(sig->cputime.totals, get_cpu());
+                times->utime = cputime_add(times->utime, cputime);
+                put_cpu_no_resched();
+        }
+}
+
+/**
+ * account_group_system_time - Maintain stime for a thread group.
+ *
+ * @tsk:        Pointer to task structure.
+ * @cputime:    Time value by which to increment the stime field of the
+ *              thread_group_cputime structure.
+ *
+ * If thread group time is being maintained, get the structure for the
+ * running CPU and update the stime field there.
+ */
+static inline void account_group_system_time(struct task_struct *tsk,
+                                             cputime_t cputime)
+{
+        struct signal_struct *sig;
+
+        /* tsk == current, ensure it is safe to use ->signal */
+        if (unlikely(tsk->exit_state))
+                return;
+
+        sig = tsk->signal;
+        if (sig->cputime.totals) {
+                struct task_cputime *times;
+
+                times = per_cpu_ptr(sig->cputime.totals, get_cpu());
+                times->stime = cputime_add(times->stime, cputime);
+                put_cpu_no_resched();
+        }
+}
+
+/**
+ * account_group_exec_runtime - Maintain exec runtime for a thread group.
+ *
+ * @tsk:        Pointer to task structure.
+ * @ns:         Time value by which to increment the sum_exec_runtime field
+ *              of the thread_group_cputime structure.
+ *
+ * If thread group time is being maintained, get the structure for the
+ * running CPU and update the sum_exec_runtime field there.
+ */
+static inline void account_group_exec_runtime(struct task_struct *tsk,
+                                              unsigned long long ns)
+{
+        struct signal_struct *sig;
+
+        sig = tsk->signal;
+        /* see __exit_signal()->task_rq_unlock_wait() */
+        barrier();
+        if (unlikely(!sig))
+                return;
+
+        if (sig->cputime.totals) {
+                struct task_cputime *times;
+
+                times = per_cpu_ptr(sig->cputime.totals, get_cpu());
+                times->sum_exec_runtime += ns;
+                put_cpu_no_resched();
+        }
+}