diff options
| author | Riley Andrews <riandrews@google.com> | 2015-10-02 00:39:53 -0700 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2016-02-16 13:52:31 -0800 |
| commit | 7abc800d049ee8e673acab90032e7cfbad1600a6 (patch) | |
| tree | f2ca8f178a59195d377538ab040667a1f4095b8d | |
| parent | b3bb0e5bbf24780300621d69e6ffbdcc11c72358 (diff) | |
sched: add sched blocked tracepoint which dumps out context of sleep.
Decare war on uninterruptible sleep. Add a tracepoint which
walks the kernel stack and dumps the first non-scheduler function
called before the scheduler is invoked.
Change-Id: I19e965d5206329360a92cbfe2afcc8c30f65c229
Signed-off-by: Riley Andrews <riandrews@google.com>
| -rw-r--r-- | include/trace/events/sched.h | 26 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 1 |
2 files changed, 26 insertions, 1 deletions
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h index 9b90c57517a9..3211890ee7d5 100644 --- a/include/trace/events/sched.h +++ b/include/trace/events/sched.h @@ -219,7 +219,7 @@ DECLARE_EVENT_CLASS(sched_process_template, DEFINE_EVENT(sched_process_template, sched_process_free, TP_PROTO(struct task_struct *p), TP_ARGS(p)); - + /* * Tracepoint for a task exiting: @@ -374,6 +374,30 @@ DEFINE_EVENT(sched_stat_template, sched_stat_blocked, TP_ARGS(tsk, delay)); /* + * Tracepoint for recording the cause of uninterruptible sleep. + */ +TRACE_EVENT(sched_blocked_reason, + + TP_PROTO(struct task_struct *tsk), + + TP_ARGS(tsk), + + TP_STRUCT__entry( + __field( pid_t, pid ) + __field( void*, caller ) + __field( bool, io_wait ) + ), + + TP_fast_assign( + __entry->pid = tsk->pid; + __entry->caller = (void*)get_wchan(tsk); + __entry->io_wait = tsk->in_iowait; + ), + + TP_printk("pid=%d iowait=%d caller=%pS", __entry->pid, __entry->io_wait, __entry->caller) +); + +/* * Tracepoint for accounting runtime (time the task is executing * on a CPU). */ diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index cfdc0e61066c..ba24bfe4ac51 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2931,6 +2931,7 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se) } trace_sched_stat_blocked(tsk, delta); + trace_sched_blocked_reason(tsk); /* * Blocking time is in units of nanosecs, so shift by |