summaryrefslogtreecommitdiff
path: root/kernel/locking
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/osq_lock.c23
1 files changed, 10 insertions, 13 deletions
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 6ef600aa0f47..1f7734949ac8 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -134,20 +134,17 @@ bool osq_lock(struct optimistic_spin_queue *lock)
* cmpxchg in an attempt to undo our queueing.
*/
- while (!READ_ONCE(node->locked)) {
- /*
- * If we need to reschedule bail... so we can block.
- * Use vcpu_is_preempted() to avoid waiting for a preempted
- * lock holder:
- */
- if (need_resched() || vcpu_is_preempted(node_cpu(node->prev)))
- goto unqueue;
-
- cpu_relax();
- }
- return true;
+ /*
+ * Wait to acquire the lock or cancelation. Note that need_resched()
+ * will come with an IPI, which will wake smp_cond_load_relaxed() if it
+ * is implemented with a monitor-wait. vcpu_is_preempted() relies on
+ * polling, be careful.
+ */
+ if (smp_cond_load_relaxed(&node->locked, VAL || need_resched() ||
+ vcpu_is_preempted(node_cpu(node->prev))))
+ return true;
-unqueue:
+ /* unqueue */
/*
* Step - A -- stabilize @prev
*