Re: [PATCH] printk: Add loglevel for "do not print to consoles".

[Steven Rostedt]

On Fri, 24 Apr 2020 23:00:01 +0900
Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> wrote:

> Since KERN_NO_CONSOLES is for -ENOMEM situations (GFP_KERNEL allocation which
> can sleep needs to invoke the OOM killer, or GFP_ATOMIC allocation which cannot
> sleep has failed), we can't create buffer on demand. For process context, it
> would be possible to create buffer upon fork() time. But for atomic context,
> it is so difficult to create buffer on demand. We could allocate shared buffer
> like logbuf but it means that we have to replicate what printk() is doing (too
> much code), for when atomic memory allocation happens resembles when printk()
> is called. Borrowing printk()'s logbuf is simpler.

I would have a buffer allocated for this at start up.

What exactly would you be "replicating" in printk? The point of printk is
to print to a console, not to be a generic ring buffer. This change is
breaking printk's most useful feature.

-- Steve