CPU getting hot or maybe not

[Adam Williamson]

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 :(
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora
http://www.happyassassin.net