powerd on 8.0, is it considered safe?

[Jeremy Chadwick]

On Mon, Mar 08, 2010 at 12:47:37PM +0200, Dan Naumov wrote:
> Is powerd finally considered stable and safe to use on 8.0? At least
> on 7.2, it consistently caused panics when used on Atom systems with
> Hyper-Threading enabled, but I recall that Attilio Rao was looking
> into it.

I didn't realise it was unsafe to use on RELENG_8 or RELENG_7...?

I've been using powerd(8) without any problems on my Supermicro X7SBA
system (CPU = Core2Duo E8400) for quite some time, including back to the
RELENG_7 days.

I should note that on RELENG_7, EIST/SpeedStep didn't appear to work
properly (cpufreq(4) driver reporting that the est piece wouldn't
attach), which historically (for me) has resulted in ACPI throttling
being done (which works).  Based on the sysctl output below, I believe
acpi_perf is in use, but I'm not 100% certain.  The man page doesn't
really disclose how to determine which driver is in use.

The X7SBA system in question is below.  Be aware I limit the lowest
clock frequency to 1500MHz using debug.cpufreq.lowest="1500" in
/boot/loader.conf, which is why you don't see anything lower in
freq_levels.

$ uname -a
FreeBSD icarus.home.lan 8.0-STABLE FreeBSD 8.0-STABLE #0: Mon Mar  1 11:51:38 PST 2010     root at icarus.home.lan:/usr/obj/usr/src/sys/X7SBA_RELENG_8_amd64  amd64

$ kenv | grep smbios.planar.product
smbios.planar.product="X7SBA"

$ uptime
 3:00am  up 6 days, 14:38, 1 user, load averages: 0.00, 0.00, 0.00

$ ps -auxwwww | grep powerd
root      991  0.0  0.0  6836  1284  ??  Ss   Mon12pm   2:42.21 /usr/sbin/powerd
jdc     71353  0.0  0.0  9036  1524   0  S+    3:00am   0:00.00 grep powerd

$ sysctl dev.cpu dev.est dev.cpufreq dev.p4tcc debug.cpufreq kern.timecounter
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.temperature: 41.0C
dev.cpu.0.freq: 1500
dev.cpu.0.freq_levels: 3000/35000 2667/28000 2333/22000 2041/19250 2000/16000 1750/14000 1500/12000
dev.cpu.0.cx_supported: C1/0 C2/85
dev.cpu.0.cx_lowest: C1
dev.cpu.0.cx_usage: 100.00% 0.00% last 500us
dev.cpu.1.%desc: ACPI CPU
dev.cpu.1.%driver: cpu
dev.cpu.1.%location: handle=\_PR_.CPU1
dev.cpu.1.%pnpinfo: _HID=none _UID=0
dev.cpu.1.%parent: acpi0
dev.cpu.1.temperature: 41.0C
dev.cpu.1.cx_supported: C1/0 C2/85
dev.cpu.1.cx_lowest: C1
dev.cpu.1.cx_usage: 100.00% 0.00% last 500us
dev.est.0.%desc: Enhanced SpeedStep Frequency Control
dev.est.0.%driver: est
dev.est.0.%parent: cpu0
dev.est.0.freq_settings: 3000/35000 2667/28000 2333/22000 2000/16000
dev.est.1.%desc: Enhanced SpeedStep Frequency Control
dev.est.1.%driver: est
dev.est.1.%parent: cpu1
dev.est.1.freq_settings: 3000/35000 2667/28000 2333/22000 2000/16000
dev.cpufreq.0.%driver: cpufreq
dev.cpufreq.0.%parent: cpu0
dev.cpufreq.1.%driver: cpufreq
dev.cpufreq.1.%parent: cpu1
dev.p4tcc.0.%desc: CPU Frequency Thermal Control
dev.p4tcc.0.%driver: p4tcc
dev.p4tcc.0.%parent: cpu0
dev.p4tcc.0.freq_settings: 10000/-1 8750/-1 7500/-1 6250/-1 5000/-1 3750/-1 2500/-1 1250/-1
dev.p4tcc.1.%desc: CPU Frequency Thermal Control
dev.p4tcc.1.%driver: p4tcc
dev.p4tcc.1.%parent: cpu1
dev.p4tcc.1.freq_settings: 10000/-1 8750/-1 7500/-1 6250/-1 5000/-1 3750/-1 2500/-1 1250/-1
debug.cpufreq.verbose: 0
debug.cpufreq.lowest: 1500
kern.timecounter.tick: 1
kern.timecounter.choice: TSC(-100) ACPI-fast(1000) i8254(0) dummy(-1000000)
kern.timecounter.hardware: ACPI-fast
kern.timecounter.stepwarnings: 0
kern.timecounter.tc.i8254.mask: 65535
kern.timecounter.tc.i8254.counter: 7127
kern.timecounter.tc.i8254.frequency: 1193182
kern.timecounter.tc.i8254.quality: 0
kern.timecounter.tc.ACPI-fast.mask: 16777215
kern.timecounter.tc.ACPI-fast.counter: 3275901
kern.timecounter.tc.ACPI-fast.frequency: 3579545
kern.timecounter.tc.ACPI-fast.quality: 1000
kern.timecounter.tc.TSC.mask: 4294967295
kern.timecounter.tc.TSC.counter: 1458979861
kern.timecounter.tc.TSC.frequency: 2992512852
kern.timecounter.tc.TSC.quality: -100
kern.timecounter.smp_tsc: 0
kern.timecounter.invariant_tsc: 1

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |