Printk Cleanups Ready For Linux 6.6 - Stepping Towards Threaded/Atomic Console Printing

A set of printk clean-ups were sent in today for the Linux 6.6 merge window. These clean-ups are important as they are a stepping stone towards the threaded / atomic console printing and in turn that is the last major blocker before the real-time (PREEMPT_RT) support can finally be upstreamed in the kernel.

John Ogness of Intel-owned Linutronix has been working on the printk clean-ups as a prereq for working toward the long-awaited threaded / atomic console printing support for non-blocking consoles. These are the clean-ups that get the printk subsystem to the stage just prior to the pending threaded/atomic code being introduced. Sadly though the threaded/atomic support itself isn't ready in time for the Linux 6.6 merge window. Hopefully it won't be much longer and in turn finally seeing the door open for mainlining real-time support that has been maintained out-of-tree for many years.

Today's printk pull has the code clean-ups, a new per-console flag for the console suspended state rather than being a global state, avoid trying to get the console lock during a panic(), documentation fixes, and other updates.