Skip to content

Commit

Permalink
[PATCH] per-task-delay-accounting: cpu delay collection via schedstats
Browse files Browse the repository at this point in the history 
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: Chandra Seetharaman <[email protected]>
Signed-off-by: Shailabh Nagar <[email protected]>
Signed-off-by: Balbir Singh <[email protected]>
Cc: Jes Sorensen <[email protected]>
Cc: Peter Chubb <[email protected]>
Cc: Erich Focht <[email protected]>
Cc: Levent Serinol <[email protected]>
Cc: Jay Lan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
  • Loading branch information
@chandra2
chandra2 authored and Linus Torvalds committed Jul 15, 2006
1 parent 0ff9224 commit 52f17b6
Show file tree
Hide file tree
Showing 2 changed files with 66 additions and 25 deletions.
20 changes: 17 additions & 3 deletions include/linux/sched.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand All @@ -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 {
Expand Down Expand Up @@ -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
{
Expand Down Expand Up @@ -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

Expand Down
71 changes: 49 additions & 22 deletions kernel/sched.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand All @@ -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
Expand Down Expand Up @@ -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);
}

/*
Expand All @@ -586,8 +608,9 @@ static void sched_info_arrive(struct task_struct *t)
*/
static inline void sched_info_queued(struct task_struct *t)
{
if (!t->sched_info.last_queued)
t->sched_info.last_queued = jiffies;
if (unlikely(sched_info_on()))
if (!t->sched_info.last_queued)
t->sched_info.last_queued = jiffies;
}

/*
Expand All @@ -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);
}

/*
Expand All @@ -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);

Expand All @@ -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:
Expand Down Expand Up @@ -1531,8 +1557,9 @@ void fastcall sched_fork(struct task_struct *p, int clone_flags)

INIT_LIST_HEAD(&p->run_list);
p->array = NULL;
#ifdef CONFIG_SCHEDSTATS
memset(&p->sched_info, 0, sizeof(p->sched_info));
#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)
p->oncpu = 0;
Expand Down

0 comments on commit 52f17b6

Please sign in to comment.