On 10/07/2015 04:45 PM, Gil Tene wrote: > For ARM, I expect WFE/SEV to need to evolve as well, and for other > reasons, even fit use within OSs. The current WFE/SEV scheme is not > scalable. While it probably works ok for spinning at the kernel > level on hardware that only has s handful of cores, the fact that > the event WFE waits for (and SEV sends) is global to the system will > break things as core counts grow (it is the hardware equivalent of > wait/notifyAll() with a single global monitor).
That's not how it works. It's sufficient to write to the lock word to wake a core from a WFE: SEV is not required. Each core has its own event monitor, and wakeup is handled by the cache coherency logic. Andrew.
