"Zeugswetter Andreas SB SD" <ZeugswetterA@spardat.at> writes:
> Unfortunately the man page for fetch_and_or does not mention anything
> about using it as a locking primitive. It is documented atomic though,
> so I guess that is enough.
You could disassemble it and see if it includes that "isync" instruction
or not.
Given Tatsuo's later report, I'm afraid the answer is "not".
regards, tom lane