Green threads are threads which are scheduled in userspace; Java 1 threads were scheduled in userspace, and Loom threads are scheduled in userspace. Loom is abs

Green threads are threads which are scheduled in userspace; Java 1 threads were scheduled in userspace, and Loom threads are scheduled in userspace. Loom is absolutely a reversion to userspace scheduling, and I think the intervening decision to delegate scheduling to the OS is something that's interesting to think about, because in hindsight it seems to have been the wrong decision. (Also, IIRC Linux didn't even have native OS threads when Java 1.0 came out, so M:1 was literally and the only option available in Linux at the time. My memory is that we had to wait for pthreads before we could have hotspot on Linux, but it's a long time ago and quite tangental to my point).