Jason Thorpe <[email protected]> wrote: >> On Jul 27, 2019, at 5:05 AM, Robert Swindells <[email protected]> wrote: >> >> I don't think the Linux futex emulation code is correct/good enough. > >I have be on/off working on an updated futex implementation written by >Taylor, with the intent of making it a native call (in order to improve >or own semaphore and mutex implementations). You are correct in that >the current implementation is lacking. > >I will try to focus on finishing up the new implementation soon. But >even the stuff written by Taylor is a little lacking compared to what >modern Linux uses futexes for, so some additional work is going to be >required.
Linux OpenJDK isn't using any extra futex features, it isn't using a bitmask to selectively wake up threads for example, it just seems to get into a loop of waking threads up then all of them going back to sleep. Robert Swindells
