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Commit fb92c34f authored by Martijn Coenen's avatar Martijn Coenen Committed by Amit Pundir
Browse files

ANDROID: binder: add RT inheritance flag to node. 



Allows a binder node to specify whether it wants to
inherit real-time scheduling policy from a caller.

Change-Id: I375b6094bf441c19f19cba06d5a6be02cd07d714
Signed-off-by: default avatarMartijn Coenen <maco@android.com>
parent 7a6edeb6

drivers/android/binder.c

+17 −5
Original line number Diff line number Diff line
@@ -358,6 +358,8 @@ struct binder_error { 
 *                        (invariant after initialized)

 * @min_priority:         minimum scheduling priority

 *                        (invariant after initialized)

 * @inherit_rt:           inherit RT scheduling policy from caller

 *                        (invariant after initialized)

 * @async_todo:           list of async work items

 *                        (protected by @proc->inner_lock)

 *
@@ -394,6 +396,7 @@ struct binder_node { 
		 * invariant after initialization

		 */

		u8 sched_policy:2;

		u8 inherit_rt:1;

		u8 accept_fds:1;

		u8 min_priority;

	};
@@ -1165,7 +1168,8 @@ static void binder_set_priority(struct task_struct *task, 


static void binder_transaction_priority(struct task_struct *task,

					struct binder_transaction *t,

					struct binder_priority node_prio)

					struct binder_priority node_prio,

					bool inherit_rt)

{

	struct binder_priority desired_prio;
@@ -1176,8 +1180,13 @@ static void binder_transaction_priority(struct task_struct *task, 
	t->saved_priority.sched_policy = task->policy;

	t->saved_priority.prio = task->normal_prio;



	if (!inherit_rt && is_rt_policy(desired_prio.sched_policy)) {

		desired_prio.prio = NICE_TO_PRIO(0);

		desired_prio.sched_policy = SCHED_NORMAL;

	} else {

		desired_prio.prio = t->priority.prio;

		desired_prio.sched_policy = t->priority.sched_policy;

	}



	if (node_prio.prio < t->priority.prio ||

	    (node_prio.prio == t->priority.prio &&
@@ -1283,6 +1292,7 @@ static struct binder_node *binder_init_node_ilocked( 
		FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT;

	node->min_priority = to_kernel_prio(node->sched_policy, priority);

	node->accept_fds = !!(flags & FLAT_BINDER_FLAG_ACCEPTS_FDS);

	node->inherit_rt = !!(flags & FLAT_BINDER_FLAG_INHERIT_RT);

	spin_lock_init(&node->lock);

	INIT_LIST_HEAD(&node->work.entry);

	INIT_LIST_HEAD(&node->async_todo);
@@ -2700,7 +2710,8 @@ static bool binder_proc_transaction(struct binder_transaction *t, 


	if (thread) {

		target_list = &thread->todo;

		binder_transaction_priority(thread->task, t, node_prio);

		binder_transaction_priority(thread->task, t, node_prio,

					    node->inherit_rt);

	} else if (!target_list) {

		target_list = &proc->todo;

	} else {
@@ -4124,7 +4135,8 @@ static int binder_thread_read(struct binder_proc *proc, 
			tr.cookie =  target_node->cookie;

			node_prio.sched_policy = target_node->sched_policy;

			node_prio.prio = target_node->min_priority;

			binder_transaction_priority(current, t, node_prio);

			binder_transaction_priority(current, t, node_prio,

						    target_node->inherit_rt);

			cmd = BR_TRANSACTION;

		} else {

			tr.target.ptr = 0;

include/uapi/linux/android/binder.h

+8 −0
Original line number Diff line number Diff line
@@ -80,6 +80,14 @@ enum flat_binder_object_flags { 
	 */

	FLAT_BINDER_FLAG_SCHED_POLICY_MASK =

		3U << FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT,



	/**

	 * @FLAT_BINDER_FLAG_INHERIT_RT: whether the node inherits RT policy

	 *

	 * Only when set, calls into this node will inherit a real-time

	 * scheduling policy from the caller (for synchronous transactions).

	 */

	FLAT_BINDER_FLAG_INHERIT_RT = 0x800,

};



#ifdef BINDER_IPC_32BIT