Re: use SIMD in GetPrivateRefCountEntry()

On Fri, Oct 24, 2025 at 4:32 PM Peter Geoghegan <pg@bowt.ie> wrote:
> I was unable to notice any improvements in any of the microbenchmarks
> that I've been using to test the index prefetching patch set. For
> whatever reason, these test cases are neither improved nor regressed
> by your patch series.

Correction: appears to be a regression at higher client counts with
standard pgbench SELECT + the index prefetching patchset + your v2
patchset. Not a massive one (about a 5% loss in TPS/throughput), and
not one that I can reproduce at lower client counts.

There are 16 physical cores on this machine, and that seems to be
around the cutoff for getting these regressions. I've disabled
turboboost and typerthreading on this machine, since I find that that
leads to more consistent performance, at least at lower client counts.

--
Peter Geoghegan