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sched: Add wait, sleep and iowait accounting tracepoints

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Add 3 schedstat tracepoints to help account for wait-time,
sleep-time and iowait-time.

They can also be used as a perf-counter source to profile tasks
on these clocks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <new-submission>
[ build fix for the !CONFIG_SCHEDSTATS case ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-07-23 20:13:26 +02:00 committed by Ingo Molnar
parent 8f0dfc34e9
commit 768d0c2722
2 changed files with 106 additions and 1 deletions
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95
include/trace/events/sched.h
View File

@ -340,6 +340,101 @@ TRACE_EVENT(sched_signal_send,
__entry->sig, __entry->comm, __entry->pid)
);
/*
* XXX the below sched_stat tracepoints only apply to SCHED_OTHER/BATCH/IDLE
* adding sched_stat support to SCHED_FIFO/RR would be welcome.
*/
/*
* Tracepoint for accounting wait time (time the task is runnable
* but not actually running due to scheduler contention).
*/
TRACE_EVENT(sched_stat_wait,
TP_PROTO(struct task_struct *tsk, u64 delay),
TP_ARGS(tsk, delay),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
__field( pid_t, pid )
__field( u64, delay )
),
TP_fast_assign(
memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
__entry->pid = tsk->pid;
__entry->delay = delay;
)
TP_perf_assign(
__perf_count(delay);
),
TP_printk("task: %s:%d wait: %Lu [ns]",
__entry->comm, __entry->pid,
(unsigned long long)__entry->delay)
);
/*
* Tracepoint for accounting sleep time (time the task is not runnable,
* including iowait, see below).
*/
TRACE_EVENT(sched_stat_sleep,
TP_PROTO(struct task_struct *tsk, u64 delay),
TP_ARGS(tsk, delay),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
__field( pid_t, pid )
__field( u64, delay )
),
TP_fast_assign(
memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
__entry->pid = tsk->pid;
__entry->delay = delay;
)
TP_perf_assign(
__perf_count(delay);
),
TP_printk("task: %s:%d sleep: %Lu [ns]",
__entry->comm, __entry->pid,
(unsigned long long)__entry->delay)
);
/*
* Tracepoint for accounting iowait time (time the task is not runnable
* due to waiting on IO to complete).
*/
TRACE_EVENT(sched_stat_iowait,
TP_PROTO(struct task_struct *tsk, u64 delay),
TP_ARGS(tsk, delay),
TP_STRUCT__entry(
__array( char, comm, TASK_COMM_LEN )
__field( pid_t, pid )
__field( u64, delay )
),
TP_fast_assign(
memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
__entry->pid = tsk->pid;
__entry->delay = delay;
)
TP_perf_assign(
__perf_count(delay);
),
TP_printk("task: %s:%d iowait: %Lu [ns]",
__entry->comm, __entry->pid,
(unsigned long long)__entry->delay)
);
#endif /* _TRACE_SCHED_H */
/* This part must be outside protection */

12
kernel/sched_fair.c
View File

@ -546,6 +546,13 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
schedstat_set(se->wait_sum, se->wait_sum +
rq_of(cfs_rq)->clock - se->wait_start);
schedstat_set(se->wait_start, 0);
#ifdef CONFIG_SCHEDSTATS
if (entity_is_task(se)) {
trace_sched_stat_wait(task_of(se),
rq_of(cfs_rq)->clock - se->wait_start);
}
#endif
}
static inline void
@ -636,8 +643,10 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->sleep_start = 0;
se->sum_sleep_runtime += delta;
if (tsk)
if (tsk) {
account_scheduler_latency(tsk, delta >> 10, 1);
trace_sched_stat_sleep(tsk, delta);
}
}
if (se->block_start) {
u64 delta = rq_of(cfs_rq)->clock - se->block_start;
@ -655,6 +664,7 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
if (tsk->in_iowait) {
se->iowait_sum += delta;
se->iowait_count++;
trace_sched_stat_iowait(tsk, delta);
}
/*