Date: Fri, 18 Nov 2022 16:28:45 -0500 From: mike tancsa <mike@sentex.net> To: FreeBSD Questions <freebsd-questions@freebsd.org> Subject: RELENG_13 and min cpu frequency Message-ID: <9d17ea30-4b10-2aa3-9d09-017da7423844@sentex.net>
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I noticed that when I moved from an old RELENG11 to RELENG13 firewall, I was starting to get dropped packets. Looking at when it was happening, it actually seems to happen at times where the network load is really low?!?! When I see a high PPS or high bandwidth, I dont get overruns on the nic. Trying to figure out whats going on, it seems to correlate with when the CPU reduces its frequency to save on power. When its in turbo mode, it scales up to 4300, but then in the quiet hours, it goes down to 800 and that seems to be when I start getting the odd overrun. e.g. printing it out every second, I see while true do /sbin/sysctl -n dev.cpu.0.freq sleep 1 done 4308 4308 4308 4308 1902 900 900 900 4308 4308 4308 4308 4308 Whats the best way to set the box NOT to scale down the CPU below a certain frequency ? I want to see if not letting it drop below 3000 prevents packet overruns when there is a burst of traffic from a time of things being quiet ? Setting debug.cpufreq.lowest: to 3000 does not seem to make a difference dev.cpu.0.cx_method: C1/hlt dev.cpu.0.cx_usage_counters: 229391593 dev.cpu.0.cx_usage: 100.00% last 87us dev.cpu.0.cx_lowest: C1 dev.cpu.0.cx_supported: C1/1/0 dev.cpu.0.freq_levels: 3400/-1 dev.cpu.0.freq: 1302 dev.cpu.0.temperature: 43.0C dev.cpu.0.coretemp.throttle_log: 0 dev.cpu.0.coretemp.tjmax: 100.0C dev.cpu.0.coretemp.resolution: 1 dev.cpu.0.coretemp.delta: 57 dev.cpu.0.%parent: acpi0 dev.cpu.0.%pnpinfo: _HID=none _UID=0 _CID=none dev.cpu.0.%location: handle=\_SB_.PR00 dev.cpu.0.%driver: cpu dev.cpu.0.%desc: ACPI CPU sysctl -A debug.cpufreq debug.cpufreq.verbose: 0 debug.cpufreq.lowest: 0 CPU is CPU: Intel(R) Xeon(R) E-2226G CPU @ 3.40GHz (3400.00-MHz K8-class CPU)
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