4 ms·
What about priority inversion? If a high QoS thread waits on a low QoS one? It seems like it would be a bigger issue here as the low QoS threads are only ever r
by Lvl999Noob 5y ago
What about priority inversion? If a high QoS thread waits on a low QoS one? It seems like it would be a bigger issue here as the low QoS threads are only ever run on half the cores.
- ejdyksen 5y agoGrand Central Dispatch (the OS-level framework that handles these QoS classes) elevates the priority of a queue if there is high priority work waiting on low priority work to finish. https://developer.apple.com/library/archive/documentation/Performance/Conceptual/EnergyGuide-iOS/PrioritizeWorkWithQoS.html#//apple_ref/doc/uid/TP40015243-CH39-SW44 https://developer.apple.com/library/archive/documentation/Pe...
- astrange 5y agoImportantly it doesn't do this for dispatch_async/dispatch_semaphore/dispatch_block_wait.