From: Riley Andrews riandrews@google.com
Use wake_up_interruptible_sync() to hint to the scheduler binder transactions are synchronous wakeups. Disable preemption while waking to avoid ping-ponging on the binder lock.
Signed-off-by: Todd Kjos tkjos@google.com Signed-off-by: Omprakash Dhyade odhyade@codeaurora.org Cc: stable stable@vger.kernel.org # 4.4+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/android/binder.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index b51fedc..6adf0bf 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2199,8 +2199,12 @@ static void binder_transaction(struct binder_proc *proc, list_add_tail(&t->work.entry, target_list); tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE; list_add_tail(&tcomplete->entry, &thread->todo); - if (target_wait) - wake_up_interruptible(target_wait); + if (target_wait) { + if (reply || !(t->flags & TF_ONE_WAY)) + wake_up_interruptible_sync(target_wait); + else + wake_up_interruptible(target_wait); + } return;
err_translate_failed: