Implementing the A Extension: Reservations, Where AMOs Run, aq/rl, FENCE
Part 20 of the RISC-V series. I compared LR/SC reservation sets, AMO atomicity, and aq/rl and FENCE implementations with a two-hart model. If reservations aren't cleared on another hart's store, the counter drops to 69.6%, and QEMU let SC succeed in all 20 runs of an ABA test.
Sunhong'sSystem Blog
RISC-V