ANDROID: binder: add min sched_policy to node.
This change adds flags to flat_binder_object.flags
to allow indicating a minimum scheduling policy for
the node. It also clarifies the valid value range
for the priority bits in the flags.
Internally, we use the priority map that the kernel
uses, e.g. [0..99] for real-time policies and [100..139]
for the SCHED_NORMAL/SCHED_BATCH policies.
Bug: 34461621
Bug: 37293077
Change-Id: I12438deecb53df432da18c6fc77460768ae726d2
Signed-off-by: Martijn Coenen <maco@google.com>
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 94fb1e6..c99b449 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -352,6 +352,8 @@
* and by @lock)
* @has_async_transaction: async transaction to node in progress
* (protected by @lock)
+ * @sched_policy: minimum scheduling policy for node
+ * (invariant after initialized)
* @accept_fds: file descriptor operations supported for node
* (invariant after initialized)
* @min_priority: minimum scheduling priority
@@ -391,6 +393,7 @@
/*
* invariant after initialization
*/
+ u8 sched_policy:2;
u8 accept_fds:1;
u8 min_priority;
};
@@ -1207,6 +1210,7 @@
binder_uintptr_t ptr = fp ? fp->binder : 0;
binder_uintptr_t cookie = fp ? fp->cookie : 0;
__u32 flags = fp ? fp->flags : 0;
+ s8 priority;
BUG_ON(!spin_is_locked(&proc->inner_lock));
while (*p) {
@@ -1238,8 +1242,10 @@
node->ptr = ptr;
node->cookie = cookie;
node->work.type = BINDER_WORK_NODE;
- node->min_priority = NICE_TO_PRIO(
- flags & FLAT_BINDER_FLAG_PRIORITY_MASK);
+ priority = flags & FLAT_BINDER_FLAG_PRIORITY_MASK;
+ node->sched_policy = (flags & FLAT_BINDER_FLAG_PRIORITY_MASK) >>
+ 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);
spin_lock_init(&node->lock);
INIT_LIST_HEAD(&node->work.entry);
@@ -4051,8 +4057,17 @@
tr.cookie = target_node->cookie;
t->saved_priority.sched_policy = current->policy;
t->saved_priority.prio = current->normal_prio;
- if (target_node->min_priority < t->priority.prio) {
- prio.sched_policy = SCHED_NORMAL;
+ if (target_node->min_priority < t->priority.prio ||
+ (target_node->min_priority == t->priority.prio &&
+ target_node->sched_policy == SCHED_FIFO)) {
+ /*
+ * In case the minimum priority on the node is
+ * higher (lower value), use that priority. If
+ * the priority is the same, but the node uses
+ * SCHED_FIFO, prefer SCHED_FIFO, since it can
+ * run unbounded, unlike SCHED_RR.
+ */
+ prio.sched_policy = target_node->sched_policy;
prio.prio = target_node->min_priority;
}
binder_set_priority(current, prio);
@@ -5091,8 +5106,9 @@
hlist_for_each_entry(ref, &node->refs, node_entry)
count++;
- seq_printf(m, " node %d: u%016llx c%016llx hs %d hw %d ls %d lw %d is %d iw %d tr %d",
+ seq_printf(m, " node %d: u%016llx c%016llx pri %d:%d hs %d hw %d ls %d lw %d is %d iw %d tr %d",
node->debug_id, (u64)node->ptr, (u64)node->cookie,
+ node->sched_policy, node->min_priority,
node->has_strong_ref, node->has_weak_ref,
node->local_strong_refs, node->local_weak_refs,
node->internal_strong_refs, count, node->tmp_refs);