Re: TSC instead of ACPI: powerd doesn't work anymore (to be expected?)

Poul-Henning Kamp <phk_at_phk.freebsd.dk> wrote:

> In message <20051028112833.7vs98zpvy808s04k_at_netchild.homeip.net>, 
> Alexander Lei
> dinger writes:
>> Hi,
>>
>> I switched the timecounter used to use the TSC instead of the ACPI one
>> (/etc/sysctl.conf). After rebooting powerd refused to start. I removed the
>> line which changes the timecounter in sysctl.conf and powerd starts again.
>>
>> Is this expected, or is this a bug?
>>
>> If this is expected:
>> - powerd fails with an unhelpful message
>
> Alexander sends unhelpful bug report without including unhelpful message :-)

:-)

I don't have the message at hand. I just had time to write the mail, but I
don't have my laptop with me to reproduce the message. But it's easy to
reproduce, just take a PC which is able to make use of powerd and switch to
using TSC as the timecounter.

> In general, if you run powerd to change your cpu clock (= TSC
> frequency), using TSC as timecounter is _not_ what you want to do.

Is it not possible to recalibrate on frequency change, or is it "just" that
nobody wrote the code do to it?

We need to document this in the powerd man-page and let powerd tell the user
if he tries to run in this unsupported mode. Any volunteers (I'm moving my
PC's to the new appartment at the weekend, so I can't volunteer)?

Bye,
Alexander.

-- 
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