amd64/157386: [powerd] Enabling powerd(8) with default settings on Intel Xeon-E3 results in system freeze

[Andriy Gapon]

The following reply was made to PR amd64/157386; it has been noted by GNATS.

From: Andriy Gapon <avg at icyb.net.ua>
To: David Graham <dgraham at unthinkable.org>, bug-followup at FreeBSD.org
Cc:  
Subject: Re: amd64/157386: [powerd] Enabling powerd(8) with default settings
 on Intel Xeon-E3 results in system freeze
Date: Tue, 31 May 2011 09:08:48 +0300

 on 29/05/2011 17:19 David Graham said the following:
 > On 05/29/11 01:59, Andriy Gapon wrote:
 >>
 >> Can you provide output of the dev.cpu sysctl and a snippet of devinfo command
 >> output that shows devices under cpu0?
 >>
 > Hi Andriy,
 > 
 > ev.cpu.0.%desc: ACPI CPU
 > dev.cpu.0.%driver: cpu
 > dev.cpu.0.%location: handle=\_SB_.CP00
 > dev.cpu.0.%pnpinfo: _HID=none _UID=0
 > dev.cpu.0.%parent: acpi0
 > dev.cpu.0.freq: 2654
 > dev.cpu.0.freq_levels: 2654/-1 2322/-1 1990/-1 1658/-1 1327/-1 995/-1 663/-1 331/-1
 > dev.cpu.0.cx_supported: C1/0
 > dev.cpu.0.cx_lowest: C1
 > dev.cpu.0.cx_usage: 100.00% last 2224us
 > 
 [snip]
 >     cpu0
 >       acpi_throttle0
 >       cpufreq0
 >     acpi_timer0
 
 I'd say that the problem is because of acpi_throttle driver, which is kind of
 dangerous and useless driver because of how it regulates frequency.
 
 I usually disable it on my Intel machines via:
 hint.acpi_throttle.0.disabled=1
 
 I am a bit surprised that acpi_perf and (dependent on it) est drivers haven't
 attached.
 
 -- 
 Andriy Gapon