[dm-devel] device-mapper: use dynamic debug instead of compile-time config option

[Hannes Reinecke]

On 5/13/20 6:25 PM, Mike Snitzer wrote:
> On Wed, May 13 2020 at  7:10am -0400,
> Hannes Reinecke <hare at suse.de> wrote:
> 
>> On 5/13/20 11:41 AM, Damien Le Moal wrote:
>>> On 2020/05/13 16:10, Hannes Reinecke wrote:
>>>> Switch to use dynamic debug to avoid having recompile the kernel
>>>> just to enable debugging messages.
>>>>
>>>> Signed-off-by: Hannes Reinecke <hare at suse.de>
>>>> ---
>>>>   include/linux/device-mapper.h | 7 +------
>>>>   1 file changed, 1 insertion(+), 6 deletions(-)
>>>>
>>>> diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
>>>> index e2d506dd805e..3d4365fd3001 100644
>>>> --- a/include/linux/device-mapper.h
>>>> +++ b/include/linux/device-mapper.h
>>>> @@ -556,13 +556,8 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
>>>>   #define DMINFO(fmt, ...) pr_info(DM_FMT(fmt), ##__VA_ARGS__)
>>>>   #define DMINFO_LIMIT(fmt, ...) pr_info_ratelimited(DM_FMT(fmt), ##__VA_ARGS__)
>>>> -#ifdef CONFIG_DM_DEBUG
>>>
>>> Can we remove this from Kconfig as a config option ?
>>>
>> No, we can't, it's being used by dm-snap and dm-integrity.
> 
> Yeah, they provide additional debugging if its set.
> 
> But shouldn't we preserve old-style DMDEBUG if CONFIG_DM_DEBUG is set
> (compile time printing of debugging) but if not set, use dynamic
> debugging?
> 
> Think I'd prefer that as the incremental improvement... thoughts?
> 
Works for me; I just don't want to recompile the kernel anytime I need 
to debug device-mapper stuff.

Will be resending.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare at suse.de                               +49 911 74053 688
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