[PlanetCCRMA] [rt-kernel] dubugging mode?

S C Rigler riglersc at gmail.com
Sun Dec 6 17:37:39 PST 2009

On Sun, 2009-12-06 at 17:24 -0800, Fernando Lopez-Lezcano wrote:
> On Sun, 2009-12-06 at 14:48 -0800, Er wrote:
> > Hi,
> > 
> > Since the F12 upgrade I got a warning when starting rt kernel saying :
> > 
> > "the debugging option is turned on in your config, it may increase 
> > buffer overrun or latency"
> > 
> > Or something like that. Indeed, it does increase my latency a 
> > lot (if I compare it to the standard kernel)! How can I switch 
> > it off?
> > 
> > Thanks for your help!
> Sorry, that is an option that is built into the kernel at compile time
> so it is not possible (AFAIK) to turn it off. I can take a look at it
> for the next build (I think it may be coming from the Fedora
> configuration files). 
> How do you determine you have more latency? What are the symptoms? I
> don't see a performance hit myself. 
> -- Fernando

I run FC10 with the vanilla 2.6.31 kernel and the rt patch which I built
using the Fedora config file (doing "make oldconfig" first).  It also
complains about CONFIG_FTRACE being on.  I grepped for "CONFIG_FTRACE"
in all of my Fedora kernel configs and couldn't find the option so it
might be something that is turned on by default if you do "make
oldconfig".  Disabling it and recompiling got rid of the message but I
haven't noticed any change wrt latency; just the message went away.

This is assuming we're talking about the same warning message though.


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