That isn't really marking cache items as not being worth writing out to memory. It's a feature for communicating with non coherent devices to tell the cache th

That isn't really marking cache items as not being worth writing out to memory. It's a feature for communicating with non coherent devices to tell the cache that any lines it might have speculatively loaded might have changed out from under it. "Not being worth" reads like cache perf management, as opposed to uses of DC CIVAC, which are strict correctness issues.