[PATCH 00/50] Add log level to show_stack()

[Steven Rostedt]

On Tue, 12 Nov 2019 13:44:47 +0900
Sergey Senozhatsky <sergey.senozhatsky.work at gmail.com> wrote:

> > > I do recall that we talked about per-CPU printk state bit which would
> > > start/end "just print it" section. We probably can extend it to "just
> > > log_store" type of functionality. Doesn't look like a very bad idea.  
> > 
> > The problem with per-CPU printk is that we would need to disable
> > interrupts.  
> 
> Or disable preemption and have loglevel per-CPU and per-context.
> preempt_count can navigate us to the right context loglevel on
> particular CPU. I'm talking here only about backtrace (error)
> reporting contexts. Those can be atomic perfectly fine.

With my real-time hat on, I'm totally against disabling of preemption
for this purpose.

-- Steve