Re: Move PinBuffer and UnpinBuffer to atomics

On 2016-03-31 06:54:02 -0400, Robert Haas wrote:
> On Wed, Mar 30, 2016 at 3:16 AM, Andres Freund <andres@anarazel.de> wrote:
> > Yea, as Tom pointed out that's not going to work.  I'll try to write a
> > patch for approach 1).
> 
> Does this mean that any platform that wants to perform well will now
> need a sub-4-byte spinlock implementation?  That's has a somewhat
> uncomfortable sound to it.

Oh. I confused my approaches. I was thinking about going for 2):

> 2) Replace the lwlock spinlock by a bit in LWLock->state. That'd avoid
>    embedding the spinlock, and actually might allow to avoid one atomic
>    op in a number of cases.

precisely because of that concern.