Re: [PATCH] Refactoring of LWLock tranches

On 2015-12-12 21:15:52 -0500, Robert Haas wrote:
> On Sat, Dec 12, 2015 at 1:17 PM, andres(at)anarazel(dot)de <andres(at)anarazel(dot)de> wrote:
> > Here's two patches doing that. The first is an adaption of your
> > constants patch, using an enum and also converting xlog.c's locks. The
> > second is the separation into distinct tranches.
>
> Personally, I prefer the #define approach to the enum, but I can live
> with doing it this way.

I think the lack needing to adjust the 'last defined' var is worth it...

> Other than that, I think these patches look
> good, although if it's OK with you I would like to make a pass over
> the comments and the commit messages which seem to me that they could
> benefit from a bit of editing (but not much substantive change).

Sounds good to me. You'll then commit that?

> > One thing to call out is that an "oversized" s_lock can now make
> > BufferDesc exceed 64 bytes, right now that's just the case when it's
> > larger than 4 bytes. I'm not sure if that's cause for real concern,
> > given that it's not very concurrent or ancient platforms where that's
> > the case.
> > http://archives.postgresql.org/message-id/20150915020625.GI9666%40alap3.anarazel.de
> > would alleviate that concern again, as it collapses flags, usage_count,
> > buf_hdr_lock and refcount into one 32 bit int...
>
> I don't think that would be worth worrying about even if we didn't
> have a plan in mind that would make it go away again, and even less so
> given that we do have such a plan.

Ok cool. I'm not particularly concerned either, just didn't want to slip
that in without having it called out.

Andres