https://www.dragonflybsd.org/docs/developer/Locking_and_Synchronization/ https://www.dragonflybsd.org/docs/developer/Locking_and_Sync... DragonlyBSD kernel has

https://www.dragonflybsd.org/docs/developer/Locking_and_Synchronization/ https://www.dragonflybsd.org/docs/developer/Locking_and_Sync... DragonlyBSD kernel has locks. Linux and most free BSDs these days use various lock-free synchronization techniques in the performance sensitive areas.