On Tue, Jan 2, 2018 at 5:23 PM, Andres Freund <andres@anarazel.de> wrote:
> To get closer to the worst case, I've also measured:
>
> pgbench SELECT 1, 16 clients, i7-6820HQ CPU (skylake):
>
> pti=off:
> tps = 420490.162391
>
> pti=on:
> tps = 350746.065039 (~0.83x)
>
> pti=on, nopcid:
> tps = 324269.903152 (~0.77x)
>
>
> Note that real-world scenarios probably will see somewhat smaller
> impact, as this was measured over a loopback unix sockets which'll have
> smaller overhead itself than proper TCP sockets + actual network.
What about scenarios with longer-running queries?
Is it feasible to think about reducing the number of system calls we
issue in cases that weren't previously worth optimizing?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company