Post Syndicated from corbet original https://lwn.net/Articles/961884/

The futex
mechanism provided by the kernel allows for the creation of efficient and
flexible locking primitives in user space. Futexes work well for many
applications, but not all. One of the exceptions, it seems, is that
perennially difficult-to-support use case: Windows games. With
this
patch series, Elizabeth Figura seeks to provide the sort of locking
that those games need, by way of a special-purpose virtual device.