> I would be surprised if this is true as it might cause missed wakeups in an ABA scenario. More importantly, what could "unchanged" even mean? For FUTEX_WAIT

> I would be surprised if this is true as it might cause missed wakeups in an ABA scenario. More importantly, what could "unchanged" even mean? For FUTEX_WAIT we provide val, a value we're saying is the value stored at the futex address, and the kernel can check that's true. But for FUTEX_WAIT val is filled out with a count - typically 1 meaning "Only wake one" or its maximum positive value meaning "everybody" although in principle if you can find a reason to wake up to 7 waiters but no more that's allowed.