evie/android_kernel_oneplus_msm8998
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ANDROID: binder: add RT inheritance flag to node.

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

Change-Id: I375b6094bf441c19f19cba06d5a6be02cd07d714
Signed-off-by: Martijn Coenen <maco@android.com>
This commit is contained in:
Martijn Coenen 2017-06-23 10:13:43 -07:00
parent 7230f99185
commit 39140a0f38
2 changed files with 25 additions and 5 deletions
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22
drivers/android/binder.c
View file

@ -359,6 +359,8 @@ 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)
*
@ -395,6 +397,7 @@ struct binder_node {
* invariant after initialization
*/
u8 sched_policy:2;
u8 inherit_rt:1;
u8 accept_fds:1;
u8 min_priority;
};
@ -1166,7 +1169,8 @@ 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;
@ -1177,8 +1181,13 @@ static void binder_transaction_priority(struct task_struct *task,
t->saved_priority.sched_policy = task->policy;
t->saved_priority.prio = task->normal_prio;
desired_prio.prio = t->priority.prio;
desired_prio.sched_policy = t->priority.sched_policy;
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);
@ -2702,7 +2712,8 @@ 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 {
@ -4100,7 +4111,8 @@ retry:
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;

8
include/uapi/linux/android/binder.h
View file

@ -79,6 +79,14 @@ 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