[gpderetta]

Reading its own values is never a problem, the writeIndex cacheline will switch from E (or M) to S (or O), but it is never evicted, so reads from it never miss. For frequent writes the read will be fulfilled by the store buffer anyway.

[rigtorp]

I think it will be invalidated due to RFO when the reader reads the write index. Only when multiple readers reads the same cache line without any intervening write will the RFO heuristic be disabled.