> Are you saying that on x86, atomic_inc() acts as a full memory barrier > but not as a compiler barrier, and vice versa for > smp_mb__after_atomic()? Or that neither atomic_inc() nor > smp_mb__after_atomic() implements a full memory barrier?
I'd say the former; AFAICT, these boil down to: https://elixir.bootlin.com/linux/v5.1-rc5/source/arch/x86/include/asm/atomic.h#L95 https://elixir.bootlin.com/linux/v5.1-rc5/source/arch/x86/include/asm/barrier.h#L84 Andrea
