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Commit 52f17b6c authored by Chandra Seetharaman's avatar Chandra Seetharaman Committed by Linus Torvalds
Browse files

[PATCH] per-task-delay-accounting: cpu delay collection via schedstats 



Make the task-related schedstats functions callable by delay accounting even
if schedstats collection isn't turned on.  This removes the dependency of
delay accounting on schedstats.

Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: default avatarShailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: default avatarBalbir Singh <balbir@in.ibm.com>
Cc: Jes Sorensen <jes@sgi.com>
Cc: Peter Chubb <peterc@gelato.unsw.edu.au>
Cc: Erich Focht <efocht@ess.nec.de>
Cc: Levent Serinol <lserinol@gmail.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 0ff92245

include/linux/sched.h

+17 −3
Original line number Diff line number Diff line
@@ -537,7 +537,7 @@ extern struct user_struct root_user; 
struct backing_dev_info;

struct reclaim_state;



#ifdef CONFIG_SCHEDSTATS

#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)

struct sched_info {

	/* cumulative counters */

	unsigned long	cpu_time,	/* time spent on the cpu */
@@ -548,9 +548,11 @@ struct sched_info { 
	unsigned long	last_arrival,	/* when we last ran on a cpu */

			last_queued;	/* when we were last queued to run */

};

#endif /* defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) */



#ifdef CONFIG_SCHEDSTATS

extern struct file_operations proc_schedstat_operations;

#endif

#endif /* CONFIG_SCHEDSTATS */



#ifdef CONFIG_TASK_DELAY_ACCT

struct task_delay_info {
@@ -580,7 +582,19 @@ struct task_delay_info { 
	u32 swapin_count;	/* total count of the number of swapin block */

				/* io operations performed */

};

#endif	/* CONFIG_TASK_DELAY_ACCT */



static inline int sched_info_on(void)

{

#ifdef CONFIG_SCHEDSTATS

	return 1;

#elif defined(CONFIG_TASK_DELAY_ACCT)

	extern int delayacct_on;

	return delayacct_on;

#else

	return 0;

#endif

}



enum idle_type

{
@@ -777,7 +791,7 @@ struct task_struct { 
	cpumask_t cpus_allowed;

	unsigned int time_slice, first_time_slice;



#ifdef CONFIG_SCHEDSTATS

#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)

	struct sched_info sched_info;

#endif

kernel/sched.c

+49 −22
Original line number Diff line number Diff line
@@ -502,9 +502,36 @@ struct file_operations proc_schedstat_operations = { 
	.release = single_release,

};



/*

 * Expects runqueue lock to be held for atomicity of update

 */

static inline void

rq_sched_info_arrive(struct rq *rq, unsigned long delta_jiffies)

{

	if (rq) {

		rq->rq_sched_info.run_delay += delta_jiffies;

		rq->rq_sched_info.pcnt++;

	}

}



/*

 * Expects runqueue lock to be held for atomicity of update

 */

static inline void

rq_sched_info_depart(struct rq *rq, unsigned long delta_jiffies)

{

	if (rq)

		rq->rq_sched_info.cpu_time += delta_jiffies;

}

# define schedstat_inc(rq, field)	do { (rq)->field++; } while (0)

# define schedstat_add(rq, field, amt)	do { (rq)->field += (amt); } while (0)

#else /* !CONFIG_SCHEDSTATS */

static inline void

rq_sched_info_arrive(struct rq *rq, unsigned long delta_jiffies)

{}

static inline void

rq_sched_info_depart(struct rq *rq, unsigned long delta_jiffies)

{}

# define schedstat_inc(rq, field)	do { } while (0)

# define schedstat_add(rq, field, amt)	do { } while (0)

#endif
@@ -524,7 +551,7 @@ static inline struct rq *this_rq_lock(void) 
	return rq;

}



#ifdef CONFIG_SCHEDSTATS

#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)

/*

 * Called when a process is dequeued from the active array and given

 * the cpu.  We should note that with the exception of interactive
@@ -552,21 +579,16 @@ static inline void sched_info_dequeued(struct task_struct *t) 
 */

static void sched_info_arrive(struct task_struct *t)

{

	unsigned long now = jiffies, diff = 0;

	struct rq *rq = task_rq(t);

	unsigned long now = jiffies, delta_jiffies = 0;



	if (t->sched_info.last_queued)

		diff = now - t->sched_info.last_queued;

		delta_jiffies = now - t->sched_info.last_queued;

	sched_info_dequeued(t);

	t->sched_info.run_delay += diff;

	t->sched_info.run_delay += delta_jiffies;

	t->sched_info.last_arrival = now;

	t->sched_info.pcnt++;



	if (!rq)

		return;



	rq->rq_sched_info.run_delay += diff;

	rq->rq_sched_info.pcnt++;

	rq_sched_info_arrive(task_rq(t), delta_jiffies);

}



/*
@@ -586,6 +608,7 @@ static void sched_info_arrive(struct task_struct *t) 
 */

static inline void sched_info_queued(struct task_struct *t)

{

	if (unlikely(sched_info_on()))

		if (!t->sched_info.last_queued)

			t->sched_info.last_queued = jiffies;

}
@@ -596,13 +619,10 @@ static inline void sched_info_queued(struct task_struct *t) 
 */

static inline void sched_info_depart(struct task_struct *t)

{

	struct rq *rq = task_rq(t);

	unsigned long diff = jiffies - t->sched_info.last_arrival;



	t->sched_info.cpu_time += diff;

	unsigned long delta_jiffies = jiffies - t->sched_info.last_arrival;



	if (rq)

		rq->rq_sched_info.cpu_time += diff;

	t->sched_info.cpu_time += delta_jiffies;

	rq_sched_info_depart(task_rq(t), delta_jiffies);

}



/*
@@ -611,7 +631,7 @@ static inline void sched_info_depart(struct task_struct *t) 
 * the idle task.)  We are only called when prev != next.

 */

static inline void

sched_info_switch(struct task_struct *prev, struct task_struct *next)

__sched_info_switch(struct task_struct *prev, struct task_struct *next)

{

	struct rq *rq = task_rq(prev);
@@ -626,10 +646,16 @@ sched_info_switch(struct task_struct *prev, struct task_struct *next) 
	if (next != rq->idle)

		sched_info_arrive(next);

}

static inline void

sched_info_switch(struct task_struct *prev, struct task_struct *next)

{

	if (unlikely(sched_info_on()))

		__sched_info_switch(prev, next);

}

#else

#define sched_info_queued(t)		do { } while (0)

#define sched_info_switch(t, next)	do { } while (0)

#endif /* CONFIG_SCHEDSTATS */

#endif /* CONFIG_SCHEDSTATS || CONFIG_TASK_DELAY_ACCT */



/*

 * Adding/removing a task to/from a priority array:
@@ -1531,7 +1557,8 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags) 


	INIT_LIST_HEAD(&p->run_list);

	p->array = NULL;

#ifdef CONFIG_SCHEDSTATS

#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)

	if (unlikely(sched_info_on()))

		memset(&p->sched_info, 0, sizeof(p->sched_info));

#endif

#if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW)