This directory holds a small collection of drafts of ideas for kernel concurrency and synchronization abstractions: rwlock/ pserialized and recursive reader-writer locks task/ lightweight asynchronous actions threadpool/ shared pools of kthreads, used by task/ and work/ work/ workqueue(9) without interprocessor synchronization Most of the code here is not tested or even compile-tested, and consists mainly of a few morning and evening hacks. Some of it may be too complicated and overengineered, but pretty much all of the design was motivated by the needs of various components in the kernel, either to help with bookkeeping that is currently ad-hoc (and often broken) or to reduce synchronization overhead. Let me (riastradh@) know if you think you would find any of this useful and want to try it out to motivate getting it into the kernel proper.