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Date:      Fri, 04 Mar 2005 11:45:07 -0800
From:      Nate Lawson <nate@root.org>
To:        Eric Anderson <anderson@centtech.com>
Cc:        freebsd-acpi@freebsd.org
Subject:   Re: System running hot / CPU freq changes randomly
Message-ID:  <4228BAC3.1020707@root.org>
In-Reply-To: <422623A6.5090605@centtech.com>
References:  <42260B46.5010100@centtech.com> <42261B72.8070602@root.org> <422623A6.5090605@centtech.com>

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Eric Anderson wrote:
> Nate Lawson wrote:
> 
>> Eric Anderson wrote:
>>
>>> I've jsut upgraded from 5.3-STABLE to -CURRENT, and have a few things 
>>> I've noticed.  One, my machine runs much hotter - it used to stay 
>>> around 40 - 41C, but not stays around 49C.  Also, it actually seems 
>>> like it's running slower - and maybe it is.  It looks like the cpu 
>>> frequency is changing all the time, hopping around from one freq to 
>>> another, for no real reason that I can tell.
>>> I'm running on a dell D600 (1.6GHZ Pentium M), with -CURRENT as of 
>>> last night.
>>> I can provide any additional information needed..
>>>
>>>
>>> Here's what I mean (on AC, not battery):
>>> [ 12:48:25 root@neutrino ~ ]# sysctl dev.cpu.0.freq
>>> dev.cpu.0.freq: 1600
>>> [ 12:48:27 root@neutrino ~ ]# sysctl dev.cpu.0.freq
>>> dev.cpu.0.freq: 400
>>> [ 12:48:28 root@neutrino ~ ]# sysctl dev.cpu.0.freq
>>> dev.cpu.0.freq: 400
>>
>>
>>
>> Are you running powerd?  If you have powerd_enable="YES" in 
>> /etc/rc.conf, it defaults to adaptive control.  I _thought_ I made the 
>> default "NO" until we get more testing.
> 
> 
> Yes, I am using it.  It was default to no, but I enabled it in hopes 
> that it would help battery life and reduce temperature.  I realized I 
> didn't really have the settings right, so after setting some lines in 
> rc.conf and restarting powerd, it seems to have stopped flopping around. 
> I'm willing to help debug/test..
> 
> 
>>> hw.acpi.cpu.cx_supported: C1/1 C2/1 C3/85 C4/185
>>> hw.acpi.cpu.cx_lowest: C1
>>> hw.acpi.cpu.cx_usage: 100.00% 0.00% 0.00% 0.00%
>>
>>
>>
>> I had to disable C2 and higher by default due to some C3 problems some 
>> users were having.  Hopefully we'll sort this out at some point and 
>> re-enable it by default.
>>
>> You can get the old values back through /etc/rc.conf.  Add:
>>
>> performance_cx_lowest="LOW"
>> economy_cx_lowest="LOW"
>>
>> (Or explicitly use "C3" if C4 doesn't work right for you).
> 
> 
> These are the settings I have right now:
> powerd_enable="YES"
> powerd_flags="-a max -b adaptive"
> performance_cx_lowest="HIGH"            # Online CPU idle state
> performance_cpu_freq="1600"             # Online CPU frequency
> economy_cx_lowest="LOW"                # Offline CPU idle state
> economy_cpu_freq="NONE"                 # Offline CPU frequency

You should not use *_cpu_freq if you're running powerd since that will 
handle the transitions for you.  The cx_lowest stuff is fine although it 
probably wouldn't hurt you to use C2 or C3 while on AC power.  It will 
save heat and I don't think affects performance much.

I'm not sure why your frequency is changing while on AC power.  You set 
"-a max".  powerd should only do adaptive stuff while on battery, 
according to your settings above.

-- 
Nate



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