Andres Freund <andres@2ndquadrant.com> writes:
> The question about platforms that simply cannot provide such atomics
> like PA-RISC, which afaics is the only one, remains tho. I am not sure
> we really want to provide codepaths that are only going to be tested
> there.
PA-RISC is a dead architecture. According to wikipedia, HP hasn't sold
any such machines since 2008, and won't support them beyond 2013. If
that really is the only case we're worried about supporting, it's an
easy decision.
What worries me more is that you mentioned several cases where the gcc
atomics exist but need kernel support. I have to think that a trap
to the kernel would make the operation so expensive as to be a serious
performance loss, not gain. So it seems to me that platforms like that
are essentially being kicked to the curb if we make this change, even
if they theoretically could still work. Are there any that we really
care about?
regards, tom lane