CPU getting hot or maybe not

[Frederic Muller]

On 01/04/2012 08:21 AM, Adam Williamson wrote:
> On Tue, 2012-01-03 at 07:24 -0600, Bruno Wolff III wrote:
>> On Tue, Jan 03, 2012 at 17:09:07 +0800,
>>    Frederic Muller<fred at cm17.com>  wrote:
>>> On 01/03/2012 04:01 PM, drago01 wrote:
>>>>
>>>> This sounds like the debug enabled kernel is causing all this (there
>>>> was a similar issue in the past iirc).
>>>> Does running the F16 kernel on top of rawhide fix your issues?
>>>
>>> How would I do that? I've altered my setup to be able to easily
>>> switch from F16 to Rawhide while still working on my 'real work' so
>>> I don't mind giving it a go (and it's fast).
>>
>> Recently I haven't been running f16 kernels on rawhide because of a
>> recent dependency change in f16 to require a higher version of a package
>> than is in rawhide. The rawhide package has the needed change so you
>> could do a nodeps install.
>>
>> The debugging kernels since 3.1 seem to be worse than they were in the
>> past. For some people this was significantly impacting their display
>> performance, for myself, my I/O performance tanked. I use luks on top
>> of raid and I think the I/O is becoming CPU bound instead of disk bound
>> on my system.
>>
>> My current solution is to rebuild kernels with most of the debug options
>> turned back off. I have a git branch with change to the debugging options
>> and when there is a new update I update my copy of the master branch,
>> megre master to my nodebug branch and then do a local build.
>
> This is what I do too, more or less - I just run 'make release' on the
> kernel spec checkout - this is what the kernel maintainers use to switch
> between 'debug' and 'release' builds - bump the rev by .1 and add a
> changelog entry, then do a scratch build. My last one is here:
>
> http://koji.fedoraproject.org/koji/taskinfo?taskID=3612350
>
> you're welcome to use it while it's still around.
>
> As Bruno says, debug kernels are much slower and also much more 'active'
> than release kernels; this could certainly explain the heat issue, as
> the laptop will rarely be able to put its CPU into sleep mode with all
> the debug activity going on.
>
> BTW, Frederic, your issue with getting an F17 nightly to boot is
> https://bugzilla.redhat.com/show_bug.cgi?id=766955 . It's well known,
> but no-one seems to be stepping up to fix it :(

Thank you everyone for all the help. I'll look into it within a day or 
two hopefully.

Fred