https://github.com/rrtreffer/ubuntu-kernel-pinephone-pro/commit/10102a890b543a8a08457dc69fa55bc032403c7d
said that there is an explanation in this commit. When the kernel sends panic, lockdep, and oops, the loglevel of console_printk will be raised to the highest, as much as possible Print log to console. Then the further explanation of this commit is that because kdump will help put these logs into dmesg, or dump the required information from vmcore, there is actually no need to increase the log level of console_printk.
And after improving, it may cause some other problems:
- may prevent panic/oops messages being printed
- take too long to flush on console resulting in watchdog reboot
The change of this commit is to add a cmdline to specify not to increase the log level when oops, panic, and lockdep occur.
Provide printk.console_no_auto_verbose boot parameter, which allows to switch off printk being verbose on oops/panic/lockdep.
Personal feeling, in fact, you can not prompt by default, but add a parameter to turn on the switch of promotion. Invert the function of this parameter.