Re: strange buzzing sound after the 2.6.10 patch

[Thomas Renninger <trenn-l3A5Bk7waGM@public.gmane.org>]

Jeremy Moles wrote:
> Try this:
> 
> edit /usr/src/linux/include/asm/param.h and change HZ to 100 (instead of
> 1000). Other folks here can perhaps comment on the side-effects, though
> I've noticed few I couldn't handle. Perhaps a divide by 0 warning with
> some programs that "guess" at the HZ, but other than that...
> 
> You'll find it only happens when the processor ACPI module is loaded. Go
> figure.
> 
> On Wed, 2005-02-23 at 21:31 -0500, Jing Su wrote:
> 
>>Hello,
>>
>>I vaguely remember someone else mentioning this problem on the list
>>before, but I don't recall if there were any answers to the solution.
>>
>>I'm running a vanilla 2.6.10 kernel patched with the acpi-2005-01-25 patch.  
>>
>>When running the patched kernel, I noticed that my laptop makes a very
>>strange and faint buzzing sound.  I've determined that the buzzing
>>sound is somewhat related to CPU and HD load.  When the CPU load is
>>heavy, or when the HD is busy, the buzzing stops.  But when the system
>>idles, the buzzing continues.  I've also tried forcing the HD to go
>>into suspension using hdparm, but the buzzing continues.
>>
>>Any hints or clues?
>>If this problem hasn't been encountered before, I'd appreciate it if
>>someone could give hints for how I can best go about isolating the
>>problem.

I heard it is because of switching C-states 1000 times a second.
Loading the processor module with max_cstates=1 or 2 should work.


      Thomas


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