Re: [RFC] printk/sysrq: Don't play with console_loglevel

From: Dmitry Safonov
Date: Tue May 28 2019 - 12:01:50 EST


Hi guys,

I see that the thread is ongoing and you understand printk code much
better than me or probably anybody :)

So, feel free to reuse it. Or I can send v1 with split sysrq/printk
parts if you think it's worth being shaped further.

I think worth to mention three "features" that you might had a chance to
miss from the current code:

1. op_p->handler(key) is not printed under console_loglevel hackery.
So, under RFC I preserved the behavior. Probably, you don't miss it
and just looking into ways to change it, but I thought worth
mentioning.
2. I've found it surprising how pr_info() interacts with pr_cont():
Basically, pr_cont() without KERN_<LEVEL> prefix will print the
resulting line with default_message_loglevel AFAIU from cont.level.
Which might be higher than warning.
I might miss a part that corrects cont.level to the first
message's level?
3. CONSOLE_LOGLEVEL_DEFAULT is config-based, so having in mind that it
can be changed and (2) - it gives me hard time to understand when
the sysrq message will be printed and when will be suppressed.

Thanks,
Dmitry