async: Add some documentation.

[safe/jmp/linux-2.6] / kernel / sched_stats.h

diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 6757925..8ab0cef 100644 (file)
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -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");
@@ -42,7 +42,8 @@ static int show_schedstat(struct seq_file *seq, void *v)
                for_each_domain(cpu, sd) {
                        enum cpu_idle_type itype;
 
-                       cpumask_scnprintf(mask_str, mask_len, sd->span);
+                       cpumask_scnprintf(mask_str, mask_len,
+                                         sched_domain_span(sd));
                        seq_printf(seq, "domain%d %s", dcount++, mask_str);
                        for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
                                        itype++) {
@@ -90,13 +91,20 @@ 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 +124,7 @@ 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 +237,6 @@ 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 +277,93 @@ 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 task_cputime *times;
+       struct signal_struct *sig;
+
+       /* tsk == current, ensure it is safe to use ->signal */
+       if (unlikely(tsk->exit_state))
+               return;
+
+       sig = tsk->signal;
+       times = &sig->cputime.totals;
+
+       spin_lock(&times->lock);
+       times->utime = cputime_add(times->utime, cputime);
+       spin_unlock(&times->lock);
+}
+
+/**
+ * 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 task_cputime *times;
+       struct signal_struct *sig;
+
+       /* tsk == current, ensure it is safe to use ->signal */
+       if (unlikely(tsk->exit_state))
+               return;
+
+       sig = tsk->signal;
+       times = &sig->cputime.totals;
+
+       spin_lock(&times->lock);
+       times->stime = cputime_add(times->stime, cputime);
+       spin_unlock(&times->lock);
+}
+
+/**
+ * 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 task_cputime *times;
+       struct signal_struct *sig;
+
+       sig = tsk->signal;
+       /* see __exit_signal()->task_rq_unlock_wait() */
+       barrier();
+       if (unlikely(!sig))
+               return;
+
+       times = &sig->cputime.totals;
+
+       spin_lock(&times->lock);
+       times->sum_exec_runtime += ns;
+       spin_unlock(&times->lock);
+}