Re: [PATCH] printk: allow setting DEFAULT_MESSAGE_LEVEL via Kconfig

From: Ryan Mallon
Date: Thu Jan 27 2011 - 15:45:14 EST

On 01/28/2011 04:57 AM, Mandeep Singh Baines wrote:
> Alexey Dobriyan (adobriyan@xxxxxxxxx) wrote:
>> On Wed, Jan 26, 2011 at 03:10:17PM -0800, Andrew Morton wrote:
>>> On Wed, 26 Jan 2011 14:57:03 -0800
>>> Randy Dunlap <rdunlap@xxxxxxxxxxxx> wrote:
>>>>> I'm a bit surprised that this wasn't already tunable at boot-time
>>>>> and/or at runtime.
>>>> As WANG Cong replied:
>>>> Why? We already have "loglevel=" kernel parameter.
>>> That's different.
>>> Mandeep's patch addresses printks which didn't have a facility level.
>> For those, we have ignore_loglevel kernel parameter.
> That's a little different. ignore_loglevel will print ALL kernel messages
> to the console. What we would like to do is look at all messages that
> are KERN_WARNING (and higher in priority) very closely. Bugs lie there;)
> Problem is that DEFAULT_MESSAGE_LEVEL is KERN_WARNING so there is too
> much noise at KERN_WARNING. So we'd like to be able to set
> DEFAULT_MESSAGE_LEVEL (default_message_loglevel) to something lower in,
> priority, at boot or earlier. You can set it via /proc/sys/kernel/printk
> (takes an int_vec) but that's too late. A ton of stuff has already been
> logged by the time we're able to change a sysctl.

Why not make printk prefix messages that have no log level with
"[NO_LOG_LEVEL]" or similar? That way the can easily be grepped out, and
it provides and incentive for people to fix them :-).


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