Re: powerd adaptive mode latching

Russell Jackson wrote:
> Powerd seems to latch at the maximum - 1 cpufreq setting while in 
> adaptive mode. This is 100% reproducible for me. It never un-wedges from 
> this state no matter how long I wait.
> 
> $ powerd -a adaptive -b adaptive -v
> powerd: using sysctl for AC line status
> powerd: using devd for AC line status
> idle time > 90%, decreasing clock speed from 1289 MHz to 966 MHz
> idle time > 90%, decreasing clock speed from 966 MHz to 644 MHz
> idle time > 90%, decreasing clock speed from 644 MHz to 322 MHz
> idle time < 65%, increasing clock speed from 322 MHz to 966 MHz
> idle time > 90%, decreasing clock speed from 966 MHz to 644 MHz
> idle time > 90%, decreasing clock speed from 644 MHz to 322 MHz
> idle time < 65%, increasing clock speed from 322 MHz to 966 MHz
> idle time < 65%, increasing clock speed from 966 MHz to 1611 MHz
> idle time < 65%, increasing clock speed from 1611 MHz to 2255 MHz
> idle time < 65%, increasing clock speed from 2255 MHz to 2579 MHz
> idle time > 90%, decreasing clock speed from 2579 MHz to 2578 MHz
> idle time > 90%, decreasing clock speed from 2579 MHz to 2578 MHz
> idle time > 90%, decreasing clock speed from 2579 MHz to 2578 MHz
> .
> .
> .
> 
> $ sysctl dev.cpu
> dev.cpu.0.%desc: ACPI CPU
> dev.cpu.0.%driver: cpu
> dev.cpu.0.%location: handle=\_PR_.CPU0
> dev.cpu.0.%pnpinfo: _HID=none _UID=0
> dev.cpu.0.%parent: acpi0
> dev.cpu.0.freq: 1289
> dev.cpu.0.freq_levels: 2579/-1 2578/-1 2255/-1 1933/-1 1611/-1 1289/-1 
> 966/-1 644/-1 322/-1
> dev.cpu.0.cx_supported: C1/1 C2/1 C3/85 C4/185
> dev.cpu.0.cx_lowest: C3
> dev.cpu.0.cx_usage: 0.00% 100.00% 0.00% 0.00%
> 
> $ sysctl dev.ichss
> dev.ichss.0.%desc: SpeedStep ICH
> dev.ichss.0.%driver: ichss
> dev.ichss.0.%parent: cpu0
> dev.ichss.0.freq_settings: 2579/-1 2578/-1
> 
> The ichss levels looked odd to me, and trying to set cpufreq=2578 is a NOOP.
> 
> $ sysctl dev.cpu.0.freq=2578
> dev.cpu.0.freq: 2579 -> 2579
> 
> I'm running 7_RELENG from about a week ago. dmesg.boot attached.
> 

I disabled ichss with hint.ichss.0.disabled=1, and the broken freq setting is gone, and
powerd operates without wedging.

So, I guess the real culprit is a broken ichss on my box; however, powerd might want to
check the value of freq after trying to set it instead of getting stuck.

-- 
Russell A. Jackson <raj_at_csub.edu>
Network Analyst
California State University, Bakersfield

If the meanings of "true" and "false" were switched,
then this sentence would not be false.