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Re: [Patch 0/2] dynamic debug
- From: Jason Baron <jbaron at redhat dot com>
- To: Greg KH <greg at kroah dot com>
- Cc: linux-kernel at vger dot kernel dot org, gnb at sgi dot com, gregkh at suse dot de, nfsv4 at linux-nfs dot org, systemtap at sources dot redhat dot com
- Date: Thu, 5 Feb 2009 13:43:04 -0500
- Subject: Re: [Patch 0/2] dynamic debug
- References: <20090205164520.GB3114@redhat.com> <20090205175849.GA936@kroah.com>
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,
-Jason
Signed-off-by: Jason Baron <jbaron@redhat.com>
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7db55ce..9e123ae 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -572,7 +572,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
dp->filename, dp->lineno,
iter->table->mod_name, dp->function,
ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
- seq_escape(m, dp->format, " \t\r\n\"");
+ seq_escape(m, dp->format, "\t\r\n\"");
seq_puts(m, "\"\n");
return 0;