[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: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Balbir 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: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sched.c b/kernel/sched.c
index 9d42cbf..b44b9a4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -502,9 +502,36 @@
.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 @@
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 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);
}
/*
@@ -586,8 +608,9 @@
*/
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;
}
/*
@@ -596,13 +619,10 @@
*/
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;
+ unsigned long delta_jiffies = jiffies - t->sched_info.last_arrival;
- t->sched_info.cpu_time += diff;
-
- 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 @@
* 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 @@
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:
@@ -1531,8 +1557,9 @@
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;
