[PATCH next v2 1/5] locking/osq_lock: Defer clearing node->locked until the slow osq_lock() path.

David Laight
2023-12-31T21:51:44Z

Since node->locked cannot be set before the assignment to prev->next
it is save to clear it in the slow path.

Signed-off-by: David Laight <david.laight@aculab.com>
---
kernel/locking/osq_lock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 75a6f6133866..e0bc74d85a76 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -97,7 +97,6 @@ bool osq_lock(struct optimistic_spin_queue *lock)
int curr = encode_cpu(smp_processor_id());
int old;

- node->locked = 0;
node->next = NULL;
node->cpu = curr;

@@ -111,6 +110,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
if (old == OSQ_UNLOCKED_VAL)
return true;

+ node->locked = 0;
prev = decode_cpu(old);
node->prev = prev;

--
2.17.1

-
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