[PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Thomas Renninger]

This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
[patch 0/3] Dynamic Debug providing early boot debug messages via boot parameter

It would be great to see these getting merged into 2.6.36...

Thanks,

        Thomas

-----

Dynamic Debug: Introduce global fake module param module.ddebug

Dynamic Debug allows enabling of pr_debug or KERN_DEBUG messages at runtime.
This is controlled via /sys/kernel/debug/dynamic_debug/control.
One major drawback is that the whole initialization of a module cannot be
tracked, because ddebug is only aware of debug strings of loaded modules.
But this is the most interesting part...

This patch introduces a fake module parameter module.ddebug(not shown in
/sys/module/*/parameters, thus it does not use any resources/memory).

If a module gets ddebug passed as a module parameter (e.g. via module.ddebug
kernel boot param or via "modprobe module ddebug"), all debug strings of this
module get activated by issuing "module module_name +p" internally
(not via sysfs) when the module gets loaded.

Possible enhancements for the future if ddebug might get extended with
further flags:
module.ddebug=flags
Then module.ddebug="p" would be the same as module.ddebug, but if there
is a "x" ddebug flag added, one could pass:
module.ddebug="xp"
which would result in such a dynamic debug query:
module module_name +xp

One not handled side-effect of this patch:
Modules must not use "ddebug" module parameter or it will get ignored.
I tried to find a compile time check, but I could not see how that
is possible. Possibly a run-time check or at least documentation (where?)
should get added, that "ddebug" must not get used as a module parameter.

Tested with:
options hp-wmi ddebug
in modprobe.conf.local
-> works and pr_debug messages issued at module initialization time show
up. Also "p" flag gets set for the whole hp-wmi module debug strings:
grep hp-wmi /sys/../dynamic_debug/control

Signed-off-by: Thomas Renninger <trenn@suse.de>

---
 include/linux/dynamic_debug.h |    5 +++++
 kernel/params.c               |    9 ++++++++-
 lib/dynamic_debug.c           |    2 +-
 3 files changed, 14 insertions(+), 2 deletions(-)

Index: linux-platform_drivers/kernel/params.c
===================================================================
--- linux-platform_drivers.orig/kernel/params.c
+++ linux-platform_drivers/kernel/params.c
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/ctype.h>
+#include <linux/dynamic_debug.h>
 
 #if 0
 #define DEBUGP printk
@@ -132,7 +133,7 @@ int parse_args(const char *name,
 	       unsigned num,
 	       int (*unknown)(char *param, char *val))
 {
-	char *param, *val;
+	char *param, *val, ddebug[1024];
 
 	DEBUGP("Parsing ARGS: %s\n", args);
 
@@ -144,6 +145,12 @@ int parse_args(const char *name,
 		int irq_was_disabled;
 
 		args = next_arg(args, &param, &val);
+		if (parameq(param, "ddebug")) {
+			sprintf(ddebug, "module %s +p", name);
+			ddebug_exec_query(ddebug);
+			continue;
+		}
+
 		irq_was_disabled = irqs_disabled();
 		ret = parse_one(param, val, params, num, unknown);
 		if (irq_was_disabled && !irqs_disabled()) {
Index: linux-platform_drivers/include/linux/dynamic_debug.h
===================================================================
--- linux-platform_drivers.orig/include/linux/dynamic_debug.h
+++ linux-platform_drivers/include/linux/dynamic_debug.h
@@ -41,6 +41,7 @@ int ddebug_add_module(struct _ddebug *ta
 
 #if defined(CONFIG_DYNAMIC_DEBUG)
 extern int ddebug_remove_module(const char *mod_name);
+extern int ddebug_exec_query(char *query_string);
 
 #define __dynamic_dbg_enabled(dd)  ({	     \
 	int __ret = 0;							     \
@@ -77,6 +78,10 @@ static inline int ddebug_remove_module(c
 {
 	return 0;
 }
+static inline int ddebug_exec_query(char *query_string)
+{
+	return 0;
+}
 
 #define dynamic_pr_debug(fmt, ...)					\
 	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
Index: linux-platform_drivers/lib/dynamic_debug.c
===================================================================
--- linux-platform_drivers.orig/lib/dynamic_debug.c
+++ linux-platform_drivers/lib/dynamic_debug.c
@@ -429,7 +429,7 @@ static int ddebug_parse_flags(const char
 	return 0;
 }
 
-static int ddebug_exec_query(char *query_string)
+int ddebug_exec_query(char *query_string)
 {
 	unsigned int flags = 0, mask = 0;
 	struct ddebug_query query;

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Thomas Renninger]

On Monday 26 July 2010 14:14:30 Thomas Renninger wrote:
> This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> [patch 0/3] Dynamic Debug providing early boot debug messages via boot parameter
> 
> It would be great to see these getting merged into 2.6.36...
and this time with some Documentation added...
Please use this patch instead of my first post.

Thanks,

         Thomas

----------

Dynamic Debug: Introduce global fake module param module.ddebug

Dynamic Debug allows enabling of pr_debug or KERN_DEBUG messages at runtime.
This is controlled via /sys/kernel/debug/dynamic_debug/control.
One major drawback is that the whole initialization of a module cannot be
tracked, because ddebug is only aware of debug strings of loaded modules.
But this is the most interesting part...

This patch introduces a fake module parameter module.ddebug(not shown in
/sys/module/*/parameters, thus it does not use any resources/memory).

If a module passes ddebug as a module parameter (e.g. via module.ddebug
kernel boot param or via "modprobe module ddebug"), all debug strings of this
module get activated by issuing "module module_name +p" internally
(not via sysfs) when the module gets loaded.

Possible enhancements for the future if ddebug might get extended with
further flags:
module.ddebug=flags
Then module.ddebug="p" would be the same as module.ddebug, but if there
is a "x" ddebug flag added, one could pass:
module.ddebug="xp"
which would result in such a dynamic debug query:
module module_name +xp

One not handled side-effect of this patch:
Modules must not use "ddebug" module parameter or it will get ignored.
I tried to find a compile time check, but I could not see how that
is possible. Possibly a run-time check or at least documentation (where?)
should get added, that "ddebug" must not get used as a module parameter.

Tested with:
options hp-wmi ddebug
in modprobe.conf
-> works and pr_debug messages issued at module initialization time show
up. Also "p" flag gets set for the whole hp-wmi module:
grep hp-wmi /sys/../dynamic_debug/control

Signed-off-by: Thomas Renninger <trenn@suse.de>

---
 Documentation/dynamic-debug-howto.txt |   28 +++++++++++++++++++++++++++-
 include/linux/dynamic_debug.h         |    5 +++++
 kernel/params.c                       |    9 ++++++++-
 lib/dynamic_debug.c                   |    2 +-
 4 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt
index 58ea64a..ebbbbdd 100644
--- a/Documentation/dynamic-debug-howto.txt
+++ b/Documentation/dynamic-debug-howto.txt
@@ -213,7 +213,7 @@ Note also that there is no convenient syntax to remove all
 the flags at once, you need to use "-psc".
 
 
-Debug messages during boot process
+Debug Messages during Boot Process
 ==================================
 
 To be able to activate debug messages during the boot process,
@@ -232,6 +232,32 @@ PCI (or other devices) initialization also is a hot candidate for using
 this boot parameter for debugging purposes.
 
 
+Debug Messages at Module Initialization Time
+============================================
+
+Enabling debug messages inside a module is only possible if the module itself
+is loaded already. If you unload a module, the dynamic debug flags associated
+to its debug messages are lost.
+Therefore, enabling debug messages that get processed at module initialization
+time through the <debugfs>/dynamic_debug/control interface is not possible.
+Instead, a "ddebug" module paramter can be passed:
+
+	- via kernel boot parameter:
+	  module.ddebug
+
+	- as an ordinary module parameter via modprobe
+	  modprobe module ddebug
+
+	- or the parameter can be used permanently via modprobe.conf(.local)
+	  options module ddebug
+
+The ddebug option is not implemented as an ordinary module parameter and thus
+will not show up in /sys/module/module_name/parameters/ddebug
+The settings can get reverted through the sysfs interface again when the
+module got loaded as soon as debug messages are not needed anymore:
+echo "module module_name -p" > <debugfs>/dynamic_debug/control
+as described in the "Command Language Reference" chapter above.
+
 Examples
 ========
 
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 52c0da4..095adf6 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -41,6 +41,7 @@ int ddebug_add_module(struct _ddebug *tab, unsigned int n,
 
 #if defined(CONFIG_DYNAMIC_DEBUG)
 extern int ddebug_remove_module(const char *mod_name);
+extern int ddebug_exec_query(char *query_string);
 
 #define __dynamic_dbg_enabled(dd)  ({	     \
 	int __ret = 0;							     \
@@ -77,6 +78,10 @@ static inline int ddebug_remove_module(const char *mod)
 {
 	return 0;
 }
+static inline int ddebug_exec_query(char *query_string)
+{
+	return 0;
+}
 
 #define dynamic_pr_debug(fmt, ...)					\
 	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
diff --git a/kernel/params.c b/kernel/params.c
index 0b30ecd..85d58e9 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -24,6 +24,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/ctype.h>
+#include <linux/dynamic_debug.h>
 
 #if 0
 #define DEBUGP printk
@@ -132,7 +133,7 @@ int parse_args(const char *name,
 	       unsigned num,
 	       int (*unknown)(char *param, char *val))
 {
-	char *param, *val;
+	char *param, *val, ddebug[1024];
 
 	DEBUGP("Parsing ARGS: %s\n", args);
 
@@ -144,6 +145,12 @@ int parse_args(const char *name,
 		int irq_was_disabled;
 
 		args = next_arg(args, &param, &val);
+		if (parameq(param, "ddebug")) {
+			sprintf(ddebug, "module %s +p", name);
+			ddebug_exec_query(ddebug);
+			continue;
+		}
+
 		irq_was_disabled = irqs_disabled();
 		ret = parse_one(param, val, params, num, unknown);
 		if (irq_was_disabled && !irqs_disabled()) {
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index a687d90..7f8ba5f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -429,7 +429,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 	return 0;
 }
 
-static int ddebug_exec_query(char *query_string)
+int ddebug_exec_query(char *query_string)
 {
 	unsigned int flags = 0, mask = 0;
 	struct ddebug_query query;

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Jason Baron]

On Mon, Jul 26, 2010 at 02:14:30PM +0200, Thomas Renninger wrote:
> This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> [patch 0/3] Dynamic Debug providing early boot debug messages via boot parameter
> 
> It would be great to see these getting merged into 2.6.36...
> 
> Thanks,
> 
>         Thomas
> 
> -----
> 
> Dynamic Debug: Introduce global fake module param module.ddebug
> 
> Dynamic Debug allows enabling of pr_debug or KERN_DEBUG messages at runtime.
> This is controlled via /sys/kernel/debug/dynamic_debug/control.
> One major drawback is that the whole initialization of a module cannot be
> tracked, because ddebug is only aware of debug strings of loaded modules.
> But this is the most interesting part...
> 
> This patch introduces a fake module parameter module.ddebug(not shown in
> /sys/module/*/parameters, thus it does not use any resources/memory).
> 
> If a module gets ddebug passed as a module parameter (e.g. via module.ddebug
> kernel boot param or via "modprobe module ddebug"), all debug strings of this
> module get activated by issuing "module module_name +p" internally
> (not via sysfs) when the module gets loaded.
> 
> Possible enhancements for the future if ddebug might get extended with
> further flags:
> module.ddebug=flags
> Then module.ddebug="p" would be the same as module.ddebug, but if there
> is a "x" ddebug flag added, one could pass:
> module.ddebug="xp"
> which would result in such a dynamic debug query:
> module module_name +xp
> 
> One not handled side-effect of this patch:
> Modules must not use "ddebug" module parameter or it will get ignored.
> I tried to find a compile time check, but I could not see how that
> is possible. Possibly a run-time check or at least documentation (where?)
> should get added, that "ddebug" must not get used as a module parameter.
> 
> Tested with:
> options hp-wmi ddebug
> in modprobe.conf.local
> -> works and pr_debug messages issued at module initialization time show
> up. Also "p" flag gets set for the whole hp-wmi module debug strings:
> grep hp-wmi /sys/../dynamic_debug/control
> 
> Signed-off-by: Thomas Renninger <trenn@suse.de>
> 
> ---
>  include/linux/dynamic_debug.h |    5 +++++
>  kernel/params.c               |    9 ++++++++-
>  lib/dynamic_debug.c           |    2 +-
>  3 files changed, 14 insertions(+), 2 deletions(-)
> 
> Index: linux-platform_drivers/kernel/params.c
> ===================================================================
> --- linux-platform_drivers.orig/kernel/params.c
> +++ linux-platform_drivers/kernel/params.c
> @@ -24,6 +24,7 @@
>  #include <linux/err.h>
>  #include <linux/slab.h>
>  #include <linux/ctype.h>
> +#include <linux/dynamic_debug.h>
>  
>  #if 0
>  #define DEBUGP printk
> @@ -132,7 +133,7 @@ int parse_args(const char *name,
>  	       unsigned num,
>  	       int (*unknown)(char *param, char *val))
>  {
> -	char *param, *val;
> +	char *param, *val, ddebug[1024];
>  
>  	DEBUGP("Parsing ARGS: %s\n", args);
>  
> @@ -144,6 +145,12 @@ int parse_args(const char *name,
>  		int irq_was_disabled;
>  
>  		args = next_arg(args, &param, &val);
> +		if (parameq(param, "ddebug")) {
> +			sprintf(ddebug, "module %s +p", name);
> +			ddebug_exec_query(ddebug);
> +			continue;
> +		}
> +
>  		irq_was_disabled = irqs_disabled();
>  		ret = parse_one(param, val, params, num, unknown);
>  		if (irq_was_disabled && !irqs_disabled()) {
> Index: linux-platform_drivers/include/linux/dynamic_debug.h
> ===================================================================
> --- linux-platform_drivers.orig/include/linux/dynamic_debug.h
> +++ linux-platform_drivers/include/linux/dynamic_debug.h
> @@ -41,6 +41,7 @@ int ddebug_add_module(struct _ddebug *ta
>  
>  #if defined(CONFIG_DYNAMIC_DEBUG)
>  extern int ddebug_remove_module(const char *mod_name);
> +extern int ddebug_exec_query(char *query_string);
>  
>  #define __dynamic_dbg_enabled(dd)  ({	     \
>  	int __ret = 0;							     \
> @@ -77,6 +78,10 @@ static inline int ddebug_remove_module(c
>  {
>  	return 0;
>  }
> +static inline int ddebug_exec_query(char *query_string)
> +{
> +	return 0;
> +}
>  
>  #define dynamic_pr_debug(fmt, ...)					\
>  	do { if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); } while (0)
> Index: linux-platform_drivers/lib/dynamic_debug.c
> ===================================================================
> --- linux-platform_drivers.orig/lib/dynamic_debug.c
> +++ linux-platform_drivers/lib/dynamic_debug.c
> @@ -429,7 +429,7 @@ static int ddebug_parse_flags(const char
>  	return 0;
>  }
>  
> -static int ddebug_exec_query(char *query_string)
> +int ddebug_exec_query(char *query_string)
>  {
>  	unsigned int flags = 0, mask = 0;
>  	struct ddebug_query query;


patch looks pretty good to me. I'm not sure how we reserve the 'ddebug'
keyword. However, I think its probably ok, if we mention it in
'kernel-parameters.txt' and in the dynamic debug documentation.

Also, ddebug could show up in /sys/module/$(modulename}/parameters/ ,
but this can probably be done in a followup patch.

Also, if 'ddebug' alone is set on the kernel command line, i'd like to
see us enable all debug statements. We could implement this by adding a
special 'meta' module to the control file which is just has a module
name of of 'All' or something like that. This could also be done in a
subsequent patch.

We also need to at least remove the 'dynamic_printk' doc from
kernel-parameters.txt.

thanks,

-Jason

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Thomas Renninger]

On Thursday 05 August 2010 17:39:10 Jason Baron wrote:
> On Mon, Jul 26, 2010 at 02:14:30PM +0200, Thomas Renninger wrote:
> > This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> > [patch 0/3] Dynamic Debug providing early boot debug messages via
> > boot parameter
> > 
> > It would be great to see these getting merged into 2.6.36...
... 
> patch looks pretty good to me. I'm not sure how we reserve the
> 'ddebug' keyword.
Yep, I also was not sure about that.
> However, I think its probably ok, if we mention it
> in 'kernel-parameters.txt' and in the dynamic debug documentation.
I added some documentation to the dynamic debug docu file and posted
the patch again (as a reply on my initial post, should be the same mail
thread).

> Also, ddebug could show up in /sys/module/$(modulename}/parameters/ ,
> but this can probably be done in a followup patch.
This was intentional.
At the time /sys is available one can also use 
/sys/kernel/debug/dynamic_debug/control
echo "module my_module_to_debug +p"
          >/sys/kernel/debug/dynamic_debug/control
would exactly do the same as /sys/module/$(modulename}/parameters
The advantage of not having it, is it saves quite some resources, in 
fact it uses none.
Otherwise every module would have an addtional parameter added with a
sysfs file associated with it with no additional functional gain.

> Also, if 'ddebug' alone is set on the kernel command line, i'd like to
> see us enable all debug statements. We could implement this by adding
> a special 'meta' module to the control file which is just has a module
> name of of 'All' or something like that. This could also be done in a
> subsequent patch.
Is there a single query which could do it?
If not, possibly a keyword like file/module called "all" could be added.
Then you could simply do that by ddebug_query="all +p"

> We also need to at least remove the 'dynamic_printk' doc from
> kernel-parameters.txt.
Don't know about this one.

So, I have your acked-by for this one?
Let's get this pushed into a tree, with some luck it still could make it
into 2.6.36? The other three have been taken by Pekka? He said something
about taking them, but I haven't received any confirmation.
Ah no, he acked-by them only.

As these are rather general ones, which tree should they go through, 
possibly Andrew could take them?
I can resubmit, if someone could tell me a list/maintainer that fits 
best, so that they really make it in...

Thanks,

         Thomas

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Greg KH]

On Thu, Aug 05, 2010 at 06:05:40PM +0200, Thomas Renninger wrote:
> On Thursday 05 August 2010 17:39:10 Jason Baron wrote:
> > On Mon, Jul 26, 2010 at 02:14:30PM +0200, Thomas Renninger wrote:
> > > This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> > > [patch 0/3] Dynamic Debug providing early boot debug messages via
> > > boot parameter
> > > 
> > > It would be great to see these getting merged into 2.6.36...
> ... 
> > patch looks pretty good to me. I'm not sure how we reserve the
> > 'ddebug' keyword.
> Yep, I also was not sure about that.
> > However, I think its probably ok, if we mention it
> > in 'kernel-parameters.txt' and in the dynamic debug documentation.
> I added some documentation to the dynamic debug docu file and posted
> the patch again (as a reply on my initial post, should be the same mail
> thread).
> 
> > Also, ddebug could show up in /sys/module/$(modulename}/parameters/ ,
> > but this can probably be done in a followup patch.
> This was intentional.
> At the time /sys is available one can also use 
> /sys/kernel/debug/dynamic_debug/control
> echo "module my_module_to_debug +p"
>           >/sys/kernel/debug/dynamic_debug/control
> would exactly do the same as /sys/module/$(modulename}/parameters
> The advantage of not having it, is it saves quite some resources, in 
> fact it uses none.
> Otherwise every module would have an addtional parameter added with a
> sysfs file associated with it with no additional functional gain.
> 
> > Also, if 'ddebug' alone is set on the kernel command line, i'd like to
> > see us enable all debug statements. We could implement this by adding
> > a special 'meta' module to the control file which is just has a module
> > name of of 'All' or something like that. This could also be done in a
> > subsequent patch.
> Is there a single query which could do it?
> If not, possibly a keyword like file/module called "all" could be added.
> Then you could simply do that by ddebug_query="all +p"
> 
> > We also need to at least remove the 'dynamic_printk' doc from
> > kernel-parameters.txt.
> Don't know about this one.
> 
> So, I have your acked-by for this one?
> Let's get this pushed into a tree, with some luck it still could make it
> into 2.6.36? The other three have been taken by Pekka? He said something
> about taking them, but I haven't received any confirmation.
> Ah no, he acked-by them only.

It's too late for .36 as none of this has been tested in linux-next yet.
How about for .37?

thanks,

greg k-h

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Jason Baron]

On Thu, Aug 05, 2010 at 06:05:40PM +0200, Thomas Renninger wrote:
> On Thursday 05 August 2010 17:39:10 Jason Baron wrote:
> > On Mon, Jul 26, 2010 at 02:14:30PM +0200, Thomas Renninger wrote:
> > > This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> > > [patch 0/3] Dynamic Debug providing early boot debug messages via
> > > boot parameter
> > > 
> > > It would be great to see these getting merged into 2.6.36...
> ... 
> > patch looks pretty good to me. I'm not sure how we reserve the
> > 'ddebug' keyword.
> Yep, I also was not sure about that.
> > However, I think its probably ok, if we mention it
> > in 'kernel-parameters.txt' and in the dynamic debug documentation.
> I added some documentation to the dynamic debug docu file and posted
> the patch again (as a reply on my initial post, should be the same mail
> thread).
> 
> > Also, ddebug could show up in /sys/module/$(modulename}/parameters/ ,
> > but this can probably be done in a followup patch.
> This was intentional.
> At the time /sys is available one can also use 
> /sys/kernel/debug/dynamic_debug/control
> echo "module my_module_to_debug +p"
>           >/sys/kernel/debug/dynamic_debug/control
> would exactly do the same as /sys/module/$(modulename}/parameters
> The advantage of not having it, is it saves quite some resources, in 
> fact it uses none.
> Otherwise every module would have an addtional parameter added with a
> sysfs file associated with it with no additional functional gain.
> 
> > Also, if 'ddebug' alone is set on the kernel command line, i'd like to
> > see us enable all debug statements. We could implement this by adding
> > a special 'meta' module to the control file which is just has a module
> > name of of 'All' or something like that. This could also be done in a
> > subsequent patch.
> Is there a single query which could do it?

I don't think so.

> If not, possibly a keyword like file/module called "all" could be added.
> Then you could simply do that by ddebug_query="all +p"
> 

ok. that makes sense. I would make the all mode apply to all future
modules that get loaded as well, just to be clear...

> > We also need to at least remove the 'dynamic_printk' doc from
> > kernel-parameters.txt.
> Don't know about this one.
> 
> So, I have your acked-by for this one?

Acked-by: Jason Baron <jbaron@redhat.com>

> Let's get this pushed into a tree, with some luck it still could make it
> into 2.6.36? The other three have been taken by Pekka? He said something
> about taking them, but I haven't received any confirmation.
> Ah no, he acked-by them only.
> 
> As these are rather general ones, which tree should they go through, 
> possibly Andrew could take them?
> I can resubmit, if someone could tell me a list/maintainer that fits 
> best, so that they really make it in...
> 
> Thanks,
> 
>          Thomas

right, originally Greg KH, pulled these into his tree. Greg, can you take
a look at pulling these into your tree? So it would be this patch, and the
thread:

Subject: [patch 0/3] Dynamic Debug providing early boot debug messages via boot parameter

thanks,

-Jason

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Greg KH]

On Thu, Aug 05, 2010 at 01:26:15PM -0400, Jason Baron wrote:
> On Thu, Aug 05, 2010 at 06:05:40PM +0200, Thomas Renninger wrote:
> > On Thursday 05 August 2010 17:39:10 Jason Baron wrote:
> > > On Mon, Jul 26, 2010 at 02:14:30PM +0200, Thomas Renninger wrote:
> > > > This patch is based on 2.6.35-rc5 + this patchset I posted recently:                                                           
> > > > [patch 0/3] Dynamic Debug providing early boot debug messages via
> > > > boot parameter
> > > > 
> > > > It would be great to see these getting merged into 2.6.36...
> > ... 
> > > patch looks pretty good to me. I'm not sure how we reserve the
> > > 'ddebug' keyword.
> > Yep, I also was not sure about that.
> > > However, I think its probably ok, if we mention it
> > > in 'kernel-parameters.txt' and in the dynamic debug documentation.
> > I added some documentation to the dynamic debug docu file and posted
> > the patch again (as a reply on my initial post, should be the same mail
> > thread).
> > 
> > > Also, ddebug could show up in /sys/module/$(modulename}/parameters/ ,
> > > but this can probably be done in a followup patch.
> > This was intentional.
> > At the time /sys is available one can also use 
> > /sys/kernel/debug/dynamic_debug/control
> > echo "module my_module_to_debug +p"
> >           >/sys/kernel/debug/dynamic_debug/control
> > would exactly do the same as /sys/module/$(modulename}/parameters
> > The advantage of not having it, is it saves quite some resources, in 
> > fact it uses none.
> > Otherwise every module would have an addtional parameter added with a
> > sysfs file associated with it with no additional functional gain.
> > 
> > > Also, if 'ddebug' alone is set on the kernel command line, i'd like to
> > > see us enable all debug statements. We could implement this by adding
> > > a special 'meta' module to the control file which is just has a module
> > > name of of 'All' or something like that. This could also be done in a
> > > subsequent patch.
> > Is there a single query which could do it?
> 
> I don't think so.
> 
> > If not, possibly a keyword like file/module called "all" could be added.
> > Then you could simply do that by ddebug_query="all +p"
> > 
> 
> ok. that makes sense. I would make the all mode apply to all future
> modules that get loaded as well, just to be clear...
> 
> > > We also need to at least remove the 'dynamic_printk' doc from
> > > kernel-parameters.txt.
> > Don't know about this one.
> > 
> > So, I have your acked-by for this one?
> 
> Acked-by: Jason Baron <jbaron@redhat.com>
> 
> > Let's get this pushed into a tree, with some luck it still could make it
> > into 2.6.36? The other three have been taken by Pekka? He said something
> > about taking them, but I haven't received any confirmation.
> > Ah no, he acked-by them only.
> > 
> > As these are rather general ones, which tree should they go through, 
> > possibly Andrew could take them?
> > I can resubmit, if someone could tell me a list/maintainer that fits 
> > best, so that they really make it in...
> > 
> > Thanks,
> > 
> >          Thomas
> 
> right, originally Greg KH, pulled these into his tree. Greg, can you take
> a look at pulling these into your tree? So it would be this patch, and the
> thread:
> 
> Subject: [patch 0/3] Dynamic Debug providing early boot debug messages via boot parameter

Ok, I'll queue this up in my tree after the 2.6.36-rc1 merge is over.
Can someone resend them to me so I don't loose them?

thanks,

greg k-h

Re: [PATCH] Dynamic Debug: Introduce global fake module param module.ddebug

[Thomas Renninger]

On Thursday 05 August 2010 07:25:54 pm Greg KH wrote:
> On Thu, Aug 05, 2010 at 06:05:40PM +0200, Thomas Renninger wrote:
> > On Thursday 05 August 2010 17:39:10 Jason Baron wrote:
...
> > So, I have your acked-by for this one?
> > Let's get this pushed into a tree, with some luck it still could make it
> > into 2.6.36? The other three have been taken by Pekka? He said something
> > about taking them, but I haven't received any confirmation.
> > Ah no, he acked-by them only.
>
> It's too late for .36 as none of this has been tested in linux-next yet.
> How about for .37?
No problem. I send you a clean patchset tomorrow.
I have one additional idea I'll try to build in:
Complain if a module uses ddebug as module parameter at module
insertion time that this is a reserved keyword/param that must not be used.

I'll leave out lkml, Andrew and Pekka (I thought they could queue these).

Thanks everybody,

     Thomas