deadlock_timeout
No restart — reload (superuser)time (ms)
How long to wait on a lock before checking whether a deadlock exists.
What it does
Deadlock detection is expensive, so PostgreSQL doesn't run it immediately — it waits deadlock_timeout (default 1 s) on a blocked lock, then checks for a cycle. It also doubles as the threshold for log_lock_waits.
How to tune it
Leave it near the default. Lowering it makes deadlocks resolve faster but runs the detector more often (overhead); raising it delays detection. If you mainly want it as the log_lock_waits threshold, tune it with that in mind.