Thanks Thomas, Just a quick update.
I just deployed this patch into a lower environment yesterday running FreeBSD 12.1 and PostgreSQL 11.6. I see a significant reduction is CPU/system load from load highs of 500+ down to the low 20’s. System CPU time has been reduced to practically nothing. I’m working with our support vendor in testing the patch and will continue to let it burn in. Hopefully, we can get the patched committed. Thanks. > On Dec 19, 2019, at 7:26 PM, Thomas Munro <thomas.mu...@gmail.com> wrote: > > It's still my intention to get this committed eventually, but I got a > bit frazzled by conflicting reports on several operating systems. For > FreeBSD, performance was improved in many cases, but there were also > some regressions that seemed to be related to ongoing work in the > kernel that seemed worth waiting for. I don't have the details > swapped into my brain right now, but there was something about a big > kernel lock for Unix domain sockets which possibly explained some > local pgbench problems, and there was also a problem relating to > wakeup priority with some test parameters, which I'd need to go and > dig up. If you want to test this and let us know how you get on, > that'd be great! Here's a rebase against PostgreSQL's master branch, > and since you mentioned PostgreSQL 11, here's a rebased version for > REL_11_STABLE in case that's easier for you to test/build via ports or > whatever and test with your production workload (eg on a throwaway > copy of your production system). You can see it's working by looking > in top: instead of state "select" (which is how poll() is reported) > you see "kqread", which on its own isn't exciting enough to get this > committed :-) >
