On Tue, 12 Nov 2019 13:44:47 +0900
Sergey Senozhatsky [off-list ref] wrote:

quoted

quoted

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