On 2013-10-16 15:49:54 -0400, Bruce Momjian wrote:
> On Sat, Oct 12, 2013 at 06:35:00PM -0700, Peter Geoghegan wrote:
> > > - ALPHA (big pain in the ass to get right, nobody uses it anymore)
> >
> > Yes, for many years now ALPHA has only been useful as a way of
> > illustrating how bad it's possible for CPU memory operation reordering
> > considerations to get. So I quite agree.
>
> Are there any optimizations we have avoided, or 'volatile' designations
> added, only for Alpha?
I am somewhat sure that some of the code we added in the last years
isn't actually correct for alpha (and others actually). It's just that
nobody actually runs on alpha anymore, so nobody notices.
> Could we improve other things if Alpha support was dropped?
I think the major thing is that if we're going to add more algorithms
that use less locks - which we'll have to, otherwise our scalability
will get more and more problematic - we'll have to adhere to the
weakest cache coherency model we support. And at least I am not
intelligent/experienced enough to blindly write correct code for Alpha.
Greetings,
Andres Freund
-- Andres Freund http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services