[PATCH v3 01/17] Add rt_nr_running accounting

Steven Rostedt
2007-11-17T06:28:44Z

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This patch adds accounting to keep track of the number of RT tasks running
on a runqueue. This information will be used in later patches.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

---
kernel/sched.c | 1 +
kernel/sched_rt.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+)

Index: linux-compile.git/kernel/sched.c
===================================================================
--- linux-compile.git.orig/kernel/sched.c 2007-11-16 11:16:38.000000000 -0500
+++ linux-compile.git/kernel/sched.c 2007-11-16 21:48:48.000000000 -0500
@@ -266,6 +266,7 @@ struct rt_rq {
struct rt_prio_array active;
int rt_load_balance_idx;
struct list_head *rt_load_balance_head, *rt_load_balance_curr;
+ unsigned long rt_nr_running;
};

/*
Index: linux-compile.git/kernel/sched_rt.c
===================================================================
--- linux-compile.git.orig/kernel/sched_rt.c 2007-11-16 11:15:56.000000000 -0500
+++ linux-compile.git/kernel/sched_rt.c 2007-11-16 21:48:48.000000000 -0500
@@ -25,12 +25,27 @@ static void update_curr_rt(struct rq *rq
curr->se.exec_start = rq->clock;
}

+static inline void inc_rt_tasks(struct task_struct *p, struct rq *rq)
+{
+ WARN_ON(!rt_task(p));
+ rq->rt.rt_nr_running++;
+}
+
+static inline void dec_rt_tasks(struct task_struct *p, struct rq *rq)
+{
+ WARN_ON(!rt_task(p));
+ WARN_ON(!rq->rt.rt_nr_running);
+ rq->rt.rt_nr_running--;
+}
+
static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup)
{
struct rt_prio_array *array = &rq->rt.active;

list_add_tail(&p->run_list, array->queue + p->prio);
__set_bit(p->prio, array->bitmap);
+
+ inc_rt_tasks(p, rq);
}

/*
@@ -45,6 +60,8 @@ static void dequeue_task_rt(struct rq *r
list_del(&p->run_list);
if (list_empty(array->queue + p->prio))
__clear_bit(p->prio, array->bitmap);
+
+ dec_rt_tasks(p, rq);
}

/*

--