Re: Re: [COMMITTERS] pgsql: Allow Pin/UnpinBuffer to operate in a lockfree manner.

On 2016-04-11 23:59:21 -0400, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
> > Will fix (both initialization and use of pg_atomic_fetch_or_u32), and
> > expand the documentation on why only atomic read/write are supposed to
> > be used.
>
> FWIW, I'd vote against adding a SpinLockInit there.

Well, it'd not be a SpinLockInit, but a pg_atomic_init_u32(), but ...

> What it would mostly
> do is prevent noticing future mistakes of the same ilk. It would be
> better no doubt if we didn't have to rely on a nearly-dead platform
> to detect this; but having such detection of a performance bug is better
> than having no detection.

Ok, works for me as well. I guess it'd be useful to add a "modern"
animal that disables spinlocks & atomics...

- Andres