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Commit 60bd5e7c authored by Martijn Coenen's avatar Martijn Coenen
Browse files

ANDROID: binder: Add thread->process_todo flag. 



This flag determines whether the thread should currently
process the work in the thread->todo worklist.

The prime usecase for this is improving the performance
of synchronous transactions: all synchronous transactions
post a BR_TRANSACTION_COMPLETE to the calling thread,
but there's no reason to return that command to userspace
right away - userspace anyway needs to wait for the reply.

Likewise, a synchronous transaction that contains a binder
object can cause a BC_ACQUIRE/BC_INCREFS to be returned to
userspace; since the caller must anyway hold a strong/weak
ref for the duration of the call, postponing these commands
until the reply comes in is not a problem.

Note that this flag is not used to determine whether a
thread can handle process work; a thread should never pick
up process work when thread work is still pending.

Before patch:
------------------------------------------------------------------
Benchmark                           Time           CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4          45959 ns      20288 ns      34351
BM_sendVec_binderize/8          45603 ns      20080 ns      34909
BM_sendVec_binderize/16         45528 ns      20113 ns      34863
BM_sendVec_binderize/32         45551 ns      20122 ns      34881
BM_sendVec_binderize/64         45701 ns      20183 ns      34864
BM_sendVec_binderize/128        45824 ns      20250 ns      34576
BM_sendVec_binderize/256        45695 ns      20171 ns      34759
BM_sendVec_binderize/512        45743 ns      20211 ns      34489
BM_sendVec_binderize/1024       46169 ns      20430 ns      34081

After patch:
------------------------------------------------------------------
Benchmark                           Time           CPU Iterations
------------------------------------------------------------------
BM_sendVec_binderize/4          42939 ns      17262 ns      40653
BM_sendVec_binderize/8          42823 ns      17243 ns      40671
BM_sendVec_binderize/16         42898 ns      17243 ns      40594
BM_sendVec_binderize/32         42838 ns      17267 ns      40527
BM_sendVec_binderize/64         42854 ns      17249 ns      40379
BM_sendVec_binderize/128        42881 ns      17288 ns      40427
BM_sendVec_binderize/256        42917 ns      17297 ns      40429
BM_sendVec_binderize/512        43184 ns      17395 ns      40411
BM_sendVec_binderize/1024       43119 ns      17357 ns      40432

Signed-off-by: default avatarMartijn Coenen <maco@android.com>

Change-Id: Ia70287066d62aba64e98ac44ff1214e37ca75693
parent 925b850c

drivers/staging/android/binder.c

+100 −44
Original line number Diff line number Diff line
@@ -597,6 +597,8 @@ enum { 
 *                        (protected by @proc->inner_lock)

 * @todo:                 list of work to do for this thread

 *                        (protected by @proc->inner_lock)

 * @process_todo:         whether work in @todo should be processed

 *                        (protected by @proc->inner_lock)

 * @return_error:         transaction errors reported by this thread

 *                        (only accessed by this thread)

 * @reply_error:          transaction errors reported by target thread
@@ -623,6 +625,7 @@ struct binder_thread { 
	bool looper_need_return; /* can be written by other thread */

	struct binder_transaction *transaction_stack;

	struct list_head todo;

	bool process_todo;

	struct binder_error return_error;

	struct binder_error reply_error;

	wait_queue_head_t wait;
@@ -810,6 +813,16 @@ static bool binder_worklist_empty(struct binder_proc *proc, 
	return ret;

}



/**

 * binder_enqueue_work_ilocked() - Add an item to the work list

 * @work:         struct binder_work to add to list

 * @target_list:  list to add work to

 *

 * Adds the work to the specified list. Asserts that work

 * is not already on a list.

 *

 * Requires the proc->inner_lock to be held.

 */

static void

binder_enqueue_work_ilocked(struct binder_work *work,

			   struct list_head *target_list)
@@ -820,22 +833,56 @@ binder_enqueue_work_ilocked(struct binder_work *work, 
}



/**

 * binder_enqueue_work() - Add an item to the work list

 * @proc:         binder_proc associated with list

 * binder_enqueue_thread_work_ilocked_nowake() - Add thread work

 * @thread:       thread to queue work to

 * @work:         struct binder_work to add to list

 * @target_list:  list to add work to

 *

 * Adds the work to the specified list. Asserts that work

 * is not already on a list.

 * Adds the work to the todo list of the thread. Doesn't set the process_todo

 * flag, which means that (if it wasn't already set) the thread will go to

 * sleep without handling this work when it calls read.

 *

 * Requires the proc->inner_lock to be held.

 */

static void

binder_enqueue_work(struct binder_proc *proc,

		    struct binder_work *work,

		    struct list_head *target_list)

binder_enqueue_thread_work_ilocked_nowake(struct binder_thread *thread,

					  struct binder_work *work)

{

	binder_inner_proc_lock(proc);

	binder_enqueue_work_ilocked(work, target_list);

	binder_inner_proc_unlock(proc);

	binder_enqueue_work_ilocked(work, &thread->todo);

}



/**

 * binder_enqueue_thread_work_ilocked() - Add an item to the thread work list

 * @thread:       thread to queue work to

 * @work:         struct binder_work to add to list

 *

 * Adds the work to the todo list of the thread, and enables processing

 * of the todo queue.

 *

 * Requires the proc->inner_lock to be held.

 */

static void

binder_enqueue_thread_work_ilocked(struct binder_thread *thread,

				   struct binder_work *work)

{

	binder_enqueue_work_ilocked(work, &thread->todo);

	thread->process_todo = true;

}



/**

 * binder_enqueue_thread_work() - Add an item to the thread work list

 * @thread:       thread to queue work to

 * @work:         struct binder_work to add to list

 *

 * Adds the work to the todo list of the thread, and enables processing

 * of the todo queue.

 */

static void

binder_enqueue_thread_work(struct binder_thread *thread,

			   struct binder_work *work)

{

	binder_inner_proc_lock(thread->proc);

	binder_enqueue_thread_work_ilocked(thread, work);

	binder_inner_proc_unlock(thread->proc);

}



static void
@@ -950,7 +997,7 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd) 
static bool binder_has_work_ilocked(struct binder_thread *thread,

				    bool do_proc_work)

{

	return !binder_worklist_empty_ilocked(&thread->todo) ||

	return thread->process_todo ||

		thread->looper_need_return ||

		(do_proc_work &&

		 !binder_worklist_empty_ilocked(&thread->proc->todo));
@@ -1367,6 +1414,17 @@ static int binder_inc_node_nilocked(struct binder_node *node, int strong, 
			node->local_strong_refs++;

		if (!node->has_strong_ref && target_list) {

			binder_dequeue_work_ilocked(&node->work);

			/*

			 * Note: this function is the only place where we queue

			 * directly to a thread->todo without using the

			 * corresponding binder_enqueue_thread_work() helper

			 * functions; in this case it's ok to not set the

			 * process_todo flag, since we know this node work will

			 * always be followed by other work that starts queue

			 * processing: in case of synchronous transactions, a

			 * BR_REPLY or BR_ERROR; in case of oneway

			 * transactions, a BR_TRANSACTION_COMPLETE.

			 */

			binder_enqueue_work_ilocked(&node->work, target_list);

		}

	} else {
@@ -1378,6 +1436,9 @@ static int binder_inc_node_nilocked(struct binder_node *node, int strong, 
					node->debug_id);

				return -EINVAL;

			}

			/*

			 * See comment above

			 */

			binder_enqueue_work_ilocked(&node->work, target_list);

		}

	}
@@ -2067,9 +2128,9 @@ static void binder_send_failed_reply(struct binder_transaction *t, 
			binder_pop_transaction_ilocked(target_thread, t);

			if (target_thread->reply_error.cmd == BR_OK) {

				target_thread->reply_error.cmd = error_code;

				binder_enqueue_work_ilocked(

					&target_thread->reply_error.work,

					&target_thread->todo);

				binder_enqueue_thread_work_ilocked(

					target_thread,

					&target_thread->reply_error.work);

				wake_up_interruptible(&target_thread->wait);

			} else {

				WARN(1, "Unexpected reply error: %u\n",
@@ -2708,11 +2769,10 @@ static bool binder_proc_transaction(struct binder_transaction *t, 
				    struct binder_proc *proc,

				    struct binder_thread *thread)

{

	struct list_head *target_list = NULL;

	struct binder_node *node = t->buffer->target_node;

	struct binder_priority node_prio;

	bool oneway = !!(t->flags & TF_ONE_WAY);

	bool wakeup = true;

	bool pending_async = false;



	BUG_ON(!node);

	binder_node_lock(node);
@@ -2722,8 +2782,7 @@ static bool binder_proc_transaction(struct binder_transaction *t, 
	if (oneway) {

		BUG_ON(thread);

		if (node->has_async_transaction) {

			target_list = &node->async_todo;

			wakeup = false;

			pending_async = true;

		} else {

			node->has_async_transaction = 1;

		}
@@ -2737,22 +2796,20 @@ static bool binder_proc_transaction(struct binder_transaction *t, 
		return false;

	}



	if (!thread && !target_list)

	if (!thread && !pending_async)

		thread = binder_select_thread_ilocked(proc);



	if (thread) {

		target_list = &thread->todo;

		binder_transaction_priority(thread->task, t, node_prio,

					    node->inherit_rt);

	} else if (!target_list) {

		target_list = &proc->todo;

		binder_enqueue_thread_work_ilocked(thread, &t->work);

	} else if (!pending_async) {

		binder_enqueue_work_ilocked(&t->work, &proc->todo);

	} else {

		BUG_ON(target_list != &node->async_todo);

		binder_enqueue_work_ilocked(&t->work, &node->async_todo);

	}



	binder_enqueue_work_ilocked(&t->work, target_list);



	if (wakeup)

	if (!pending_async)

		binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */);



	binder_inner_proc_unlock(proc);
@@ -3254,10 +3311,10 @@ static void binder_transaction(struct binder_proc *proc, 
		}

	}

	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;

	binder_enqueue_work(proc, tcomplete, &thread->todo);

	t->work.type = BINDER_WORK_TRANSACTION;



	if (reply) {

		binder_enqueue_thread_work(thread, tcomplete);

		binder_inner_proc_lock(target_proc);

		if (target_thread->is_dead) {

			binder_inner_proc_unlock(target_proc);
@@ -3265,7 +3322,7 @@ static void binder_transaction(struct binder_proc *proc, 
		}

		BUG_ON(t->buffer->async_transaction != 0);

		binder_pop_transaction_ilocked(target_thread, in_reply_to);

		binder_enqueue_work_ilocked(&t->work, &target_thread->todo);

		binder_enqueue_thread_work_ilocked(target_thread, &t->work);

		binder_inner_proc_unlock(target_proc);

		wake_up_interruptible_sync(&target_thread->wait);

		binder_restore_priority(current, in_reply_to->saved_priority);
@@ -3273,6 +3330,7 @@ static void binder_transaction(struct binder_proc *proc, 
	} else if (!(t->flags & TF_ONE_WAY)) {

		BUG_ON(t->buffer->async_transaction != 0);

		binder_inner_proc_lock(proc);

		binder_enqueue_thread_work_ilocked_nowake(thread, tcomplete);

		t->need_reply = 1;

		t->from_parent = thread->transaction_stack;

		thread->transaction_stack = t;
@@ -3286,6 +3344,7 @@ static void binder_transaction(struct binder_proc *proc, 
	} else {

		BUG_ON(target_node == NULL);

		BUG_ON(t->buffer->async_transaction != 1);

		binder_enqueue_thread_work(thread, tcomplete);

		if (!binder_proc_transaction(t, target_proc, NULL))

			goto err_dead_proc_or_thread;

	}
@@ -3365,15 +3424,11 @@ err_invalid_target_handle: 
	if (in_reply_to) {

		binder_restore_priority(current, in_reply_to->saved_priority);

		thread->return_error.cmd = BR_TRANSACTION_COMPLETE;

		binder_enqueue_work(thread->proc,

				    &thread->return_error.work,

				    &thread->todo);

		binder_enqueue_thread_work(thread, &thread->return_error.work);

		binder_send_failed_reply(in_reply_to, return_error);

	} else {

		thread->return_error.cmd = return_error;

		binder_enqueue_work(thread->proc,

				    &thread->return_error.work,

				    &thread->todo);

		binder_enqueue_thread_work(thread, &thread->return_error.work);

	}

}
@@ -3677,10 +3732,9 @@ static int binder_thread_write(struct binder_proc *proc, 
					WARN_ON(thread->return_error.cmd !=

						BR_OK);

					thread->return_error.cmd = BR_ERROR;

					binder_enqueue_work(

						thread->proc,

						&thread->return_error.work,

						&thread->todo);

					binder_enqueue_thread_work(

						thread,

						&thread->return_error.work);

					binder_debug(

						BINDER_DEBUG_FAILED_TRANSACTION,

						"%d:%d BC_REQUEST_DEATH_NOTIFICATION failed\n",
@@ -3760,9 +3814,9 @@ static int binder_thread_write(struct binder_proc *proc, 
					if (thread->looper &

					    (BINDER_LOOPER_STATE_REGISTERED |

					     BINDER_LOOPER_STATE_ENTERED))

						binder_enqueue_work_ilocked(

								&death->work,

								&thread->todo);

						binder_enqueue_thread_work_ilocked(

								thread,

								&death->work);

					else {

						binder_enqueue_work_ilocked(

								&death->work,
@@ -3817,8 +3871,8 @@ static int binder_thread_write(struct binder_proc *proc, 
				if (thread->looper &

					(BINDER_LOOPER_STATE_REGISTERED |

					 BINDER_LOOPER_STATE_ENTERED))

					binder_enqueue_work_ilocked(

						&death->work, &thread->todo);

					binder_enqueue_thread_work_ilocked(

						thread, &death->work);

				else {

					binder_enqueue_work_ilocked(

							&death->work,
@@ -3992,6 +4046,8 @@ retry: 
			break;

		}

		w = binder_dequeue_work_head_ilocked(list);

		if (binder_worklist_empty_ilocked(&thread->todo))

			thread->process_todo = false;



		switch (w->type) {

		case BINDER_WORK_TRANSACTION: {