Re: printk: what is going on with additional newlines?

Linus Torvalds
2017-08-29T17:12:26Z

On Tue, Aug 29, 2017 at 10:00 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> I refuse to help those things. We mis-designed things

Actually, let me rephrase that:

It might actually be a good idea to help those things, by making
helper functions available that do the marshalling.

So not calling "printk()" directly, but having a set of simple
"buffer_print()" functions where each user has its own buffer, and
then the "buffer_print()" functions will help people do nicely output
data.

So if the issue is that people want to print (for example) hex dumps
one character at a time, but don't want to have each character show up
on a line of their own, I think we might well add a few functions to
help dop that.

But they wouldn't be "printk". They would be the buffering functions
that then call printk when tyhey have buffered a line.

That avoids the whole nasty issue with printk - printk wants to show
stuff early (because _maybe_ it's critical) and printk wants to make
log records with timestamps and loglevels. And printk has serious
locking issues that are really nasty and fundamental.

A private buffer has none of those issues.

Linus