[PATCH 13/13] ANDROID: binder: Add tracing for binder priority inheritance.

Martijn Coenen
2017-08-25T09:34:09Z

This allows to easily trace and visualize priority inheritance
in the binder driver.

Change-Id: I8449ae4b002e55c5e9517a47f3581e05eef051d8
Signed-off-by: Martijn Coenen <maco@android.com>
---
drivers/android/binder.c | 4 ++++
drivers/android/binder_trace.h | 24 ++++++++++++++++++++++++
2 files changed, 28 insertions(+)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 337c88fd675d..b29af3de6c34 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1153,6 +1153,10 @@ static void binder_do_set_priority(struct task_struct *task,
task->pid, desired.prio,
to_kernel_prio(policy, priority));

+ trace_binder_set_priority(task->tgid, task->pid, task->normal_prio,
+ to_kernel_prio(policy, priority),
+ desired.prio);
+
/* Set the actual priority */
if (task->policy != policy || is_rt_policy(policy)) {
struct sched_param params;
diff --git a/drivers/android/binder_trace.h b/drivers/android/binder_trace.h
index 7967db16ba5a..1e0169796d81 100644
--- a/drivers/android/binder_trace.h
+++ b/drivers/android/binder_trace.h
@@ -85,6 +85,30 @@ DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_ioctl_done);
DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_write_done);
DEFINE_BINDER_FUNCTION_RETURN_EVENT(binder_read_done);

+TRACE_EVENT(binder_set_priority,
+ TP_PROTO(int proc, int thread, unsigned int old_prio,
+ unsigned int desired_prio, unsigned int new_prio),
+ TP_ARGS(proc, thread, old_prio, new_prio, desired_prio),
+
+ TP_STRUCT__entry(
+ __field(int, proc)
+ __field(int, thread)
+ __field(unsigned int, old_prio)
+ __field(unsigned int, new_prio)
+ __field(unsigned int, desired_prio)
+ ),
+ TP_fast_assign(
+ __entry->proc = proc;
+ __entry->thread = thread;
+ __entry->old_prio = old_prio;
+ __entry->new_prio = new_prio;
+ __entry->desired_prio = desired_prio;
+ ),
+ TP_printk("proc=%d thread=%d old=%d => new=%d desired=%d",
+ __entry->proc, __entry->thread, __entry->old_prio,
+ __entry->new_prio, __entry->desired_prio)
+);
+
TRACE_EVENT(binder_wait_for_work,
TP_PROTO(bool proc_work, bool transaction_stack, bool thread_todo),
TP_ARGS(proc_work, transaction_stack, thread_todo),
--
2.14.1.480.gb18f417b89-goog