On Wed, Nov 17, 2021 at 11:00:10AM +0300, Dev Op wrote: > I was dealing with one router and faced with the fact that I did not see > hypertrading after installing OpenBSD 7.0. I came across an email > https://www.mail-archive.com/[email protected]/msg99141.html, > where I read hypertrading was disabled for Intel processors running on > OpenBSD/amd64 and that it can be enabled via hw.smt. I did so, but I don't > see it making a difference. How do you make sure it's on and used?
Hyperthreading is not 'disabled' by the OpenBSD kernel in the same way that it can be disabled in the BIOS. All cores will be detected and active by the MP kernel, but no processes will be scheduled on the HT cores. What 'difference' are you expecting to see, anyway? > dmesg.boot is here: https://pastebin.com/G24A7Jbw Please include the full dmesg inline in future. > The following services worked before the updates: pf / CARP / ospfd / > zabbix-proxy / snmpd. I would be surprised if this machine is actually CPU bound, and that enabling HT would show a meaningful performance increase for your application. Also note that HT is unused by default in OpenBSD for good reasons that have been discussed and explained on the mailing lists before.
