Hi,
On 2016-09-13 16:08:39 +0300, Heikki Linnakangas wrote: > So, if I've understood correctly, the purpose of this patch is to improve > performance on a multi-CPU system, which has the kqueue() function. Most > notably, FreeBSD? I think it's not necessarily about the current system, but more about future uses of the WaitEventSet stuff. Some of that is going to use a lot more sockets. E.g. doing a parallel append over FDWs. > I launched a FreeBSD 10.3 instance on Amazon EC2 (ami-e0682b80), on a > m4.10xlarge instance. That's a 40 core system, biggest available, I believe. > I built PostgreSQL master on it, and ran pgbench to benchmark: > > pgbench -i -s 200 postgres > pgbench -M prepared -j 36 -c 36 -S postgres -T20 -P1 This seems likely to actually seldomly exercise the relevant code path. We only do the poll()/epoll_wait()/... when a read() doesn't return anything, but that seems likely to seldomly occur here. Using a lower thread count and a lot higher client count might change that. Note that the case where poll vs. epoll made a large difference (after the regression due to ac1d7945f86) on linux was only on fairly large machines, with high clients counts. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers