Re: [PATCH A+B] pmem: Add prints at module load and unload

From: Greg KH
Date: Mon Apr 13 2015 - 09:36:15 EST


On Mon, Apr 13, 2015 at 04:20:37PM +0300, Boaz Harrosh wrote:
> On 04/13/2015 03:36 PM, Greg KH wrote:
> > if you are relying on kernel log messages for
> > specific things to happen in your system, you are doing it wrong as they
> > can change and disappear in any future kernel release, they are NOT an
> > api.
> >
>
> Again. I am not doing anything with these messages. Yes messages are not
> API. I do not need them for a live and running system, at all.
>
> I need it for a dead system. for a long dead system. A system that has failed
> 3 days ago and all I have is the system/application logs and the Kernel logs.
>
> I guess I'm antic and you guys have other means for these things, I wish to
> learn then. So far all we are asking to keep are the logs, Is there something
> else I need to store from a *past* running system?
>
> Until now this gave me a very good place to start my investigation. With
> empty log files, how do I then proceed?

What would this simple "the device was removed" log message help you out
with on a dead and old system?

Same goes for the "device found!" message, how does that help anyone
out? If they do help in some manner with debugging, then make them
debugging messages, and enable them on your systems when doing testing.
But for general purpose systems, if they don't do anything except be
noisy, might as well turn them off, right?

thanks,

greg k-h
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