Hi, On 2022-09-26 21:02:08 -0700, Andres Freund wrote: > The x86 mac VMs from cirrus-ci claim to have 12 CPUs, but when working on > initdb caching for tests I noticed that using all those CPUs for tests hurts > the test times noticably. > > See [1] (note that the overall time is influenced by different degrees of > cache hit ratios): > > concurrency test time: > 4 05:58 > 6 05:09 > 8 04:58 > 10 05:58 > 12 (current) 06:58 > > There's a fair bit of run-to-run variance, but the rough shape of these > looks repeatable. > > I suspect the VMs might be overcommitted a fair bit - or macos just scales > poorly. Cirrus-ci apparently is switching to M1 based macs, which could be > related. It'd be good for us do that switch, as it'd give use ARM coverage for > CI / cfbot. See also [3]. > > > In 15 (and thus autoconf) the timings differ a bit less [2]: > > concurrency test time: > 4 06:54 > 6 05:43 > 8 06:09 > 10 06:01 > 12 (current) 06:38 > > Looks like changing TEST_JOBS=6 or 8 would be a good idea.
Set it to 8 now. Greetings, Andres Freund
