[tip:perfcounters/core] perf_counter, sched: Add sched_stat_runtime tracepoint

tip-bot for Ingo Molnar
2009-09-15T09:36:17Z

Commit-ID: f977bb4937857994312fff4f9c2cad336a36a932
Gitweb: http://git.kernel.org/tip/f977bb4937857994312fff4f9c2cad336a36a932
Author: Ingo Molnar <mingo@elte.hu>
AuthorDate: Sun, 13 Sep 2009 18:15:54 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 13 Sep 2009 18:17:28 +0200

perf_counter, sched: Add sched_stat_runtime tracepoint

This allows more precise tracking of how the scheduler accounts
(and acts upon) a task having spent N nanoseconds of CPU time.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
include/trace/events/sched.h | 33 +++++++++++++++++++++++++++++++++
kernel/sched_fair.c | 1 +
2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index b48f1ad..4069c43 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -380,6 +380,39 @@ TRACE_EVENT(sched_stat_wait,
);

/*
+ * Tracepoint for accounting runtime (time the task is executing
+ * on a CPU).
+ */
+TRACE_EVENT(sched_stat_runtime,
+
+ TP_PROTO(struct task_struct *tsk, u64 runtime, u64 vruntime),
+
+ TP_ARGS(tsk, runtime, vruntime),
+
+ TP_STRUCT__entry(
+ __array( char, comm, TASK_COMM_LEN )
+ __field( pid_t, pid )
+ __field( u64, runtime )
+ __field( u64, vruntime )
+ ),
+
+ TP_fast_assign(
+ memcpy(__entry->comm, tsk->comm, TASK_COMM_LEN);
+ __entry->pid = tsk->pid;
+ __entry->runtime = runtime;
+ __entry->vruntime = vruntime;
+ )
+ TP_perf_assign(
+ __perf_count(runtime);
+ ),
+
+ TP_printk("task: %s:%d runtime: %Lu [ns], vruntime: %Lu [ns]",
+ __entry->comm, __entry->pid,
+ (unsigned long long)__entry->runtime,
+ (unsigned long long)__entry->vruntime)
+);
+
+/*
* Tracepoint for accounting sleep time (time the task is not runnable,
* including iowait, see below).
*/
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index aa7f841..a097e90 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -513,6 +513,7 @@ static void update_curr(struct cfs_rq *cfs_rq)
if (entity_is_task(curr)) {
struct task_struct *curtask = task_of(curr);

+ trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
cpuacct_charge(curtask, delta_exec);
account_group_exec_runtime(curtask, delta_exec);
}