Re: [Patch 0/2] dynamic debug

[Greg KH <greg@kroah.com>]

On Thu, Feb 05, 2009 at 01:43:04PM -0500, Jason Baron wrote:
> On Thu, Feb 05, 2009 at 09:58:49AM -0800, Greg KH wrote:
> > On Thu, Feb 05, 2009 at 11:45:20AM -0500, Jason Baron wrote:
> > > hi,
> > > 
> > > This patchset combines Greg Bank's dprintk() patchset with the dynamic printk
> > > patchset. We are renaming the combined solution 'dynamic debug'. As a reminder,
> > > the patchset allows debug printk style statements to be dynamically 
> > > enabled/disabled at runtime.
> > > 
> > > The key new feature of this patchset is a richer /debugfs control file
> > > interface, (an example output from my system is at the bottom), which allows
> > > fined grained control over the the debug output. The output can be controlled by
> > > function, file and line number, module, and format string. 
> > 
> > That's nice, but do we really need to have that kind of control?  It
> > seems like overkill.
> > 
> 
> given the ability of this feature to very quickly fill the logs, I think
> it makes sense for some cases. Also, Greg found it very useful in his debugging
> work...
> 
> > > For example, to enable all debug statement in module 'nf_conntrack':
> > > 
> > > #echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control
> > > 
> > > A further explanation can be found in the documentation patch.
> > > 
> > > While adding these new features we have dropped a couple that we intend to add
> > > back in subsequent patches. The ability to turn on/off all debugging at once,
> > > either via the /debugfs control file, or via the kernel command line.
> > > 
> > > thanks,
> > > 
> > > -Jason and Greg
> > > 
> > > 
> > > # filename:lineno [module]function flags format
> > > arch/x86/kernel/setup_percpu.c:260 [setup_percpu]numa_set_node - "Setting\040node\040for\040non-present\040cpu\040%d\012"
> > 
> > Why the \040 syntax?  Can't we handle a space in a string?  Makes it
> > very hard to grep for things...
> > 
> 
> ok, patch below resolves the space issue.

Thanks, I've merged this with the main version.

greg k-h