On 28/09/2018 14:19, Thomas Munro wrote: > On Fri, Sep 28, 2018 at 11:09 AM Andres Freund <and...@anarazel.de> wrote: >> On 2018-09-28 10:55:13 +1200, Thomas Munro wrote: >>> Matteo Beccati reported a 5-10% performance drop on a >>> low-end Celeron NetBSD box which we have no explanation for, and we >>> have no reports from server-class machines on that OS -- so perhaps we >>> (or the NetBSD port?) should consider building with WAIT_USE_POLL on >>> NetBSD until someone can figure out what needs to be fixed there >>> (possibly on the NetBSD side)? >> >> Yea, I'm not too worried about that. It'd be great to test that, but >> otherwise I'm also ok to just plonk that into the template. > > Thanks for the review! Ok, if we don't get a better idea I'll put > this in src/template/netbsd: > > CPPFLAGS="$CPPFLAGS -DWAIT_USE_POLL"
A quick test on a 8 vCPU / 4GB RAM virtual machine running a fresh install of NetBSD 8.0 again shows that kqueue is consistently slower running pgbench vs unpatched master on tcp-b like pgbench workloads: ~1200tps vs ~1400tps w/ 96 clients and threads, scale factor 10 while on select only benchmarks the difference is below the noise floor, with both doing roughly the same ~30k tps. Out of curiosity, I've installed FreBSD on an identically specced VM, and the select benchmark was ~75k tps for kqueue vs ~90k tps on unpatched master, so maybe there's something wrong I'm doing when benchmarking. Could you please provide proper instructions? Cheers -- Matteo Beccati Development & Consulting - http://www.beccati.com/