[GIT PULL] printk fixups for 5.19-rc4

From: Petr Mladek
Date: Thu Jun 23 2022 - 16:23:52 EST


Hi Linus,

please pull the revert of printk console kthreads from

git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux.git tags/printk-for-5.19-rc4

We, printk maintainers, really appreciate that you gave us
the chance to try the console kthreads in 5.19 release candidates.
We expected some problems and were able so solve them. But
the missing synchronization between early and normal consoles
made us nervous. We would like to review all console drivers and
look for this kind of expectations that were provided by the original
code.

There are many console drivers and the review will take some time.
We do not want to risk bigger changes late in the release cycle
and problems in the released 5.19. We prefer to revert it now.

Thanks a lot for the chance and sorry for the troubles.
We have new material for improvements.

=========================================

- Revert printk console kthreads. The testing of 5.19 release candidates
revealed issues that did not happen when all consoles were serialized
using the console semaphore. More time is needed to check expectations
of the existing console drivers and be confident that they can
be safely used in parallel.

----------------------------------------------------------------
Petr Mladek (7):
Revert "printk: Wait for the global console lock when the system is going down"
Revert "printk: Block console kthreads when direct printing will be required"
Revert "printk: remove @console_locked"
Revert "printk: extend console_lock for per-console locking"
Revert "printk: add kthread console printers"
Revert "printk: add functions to prefer direct printing"
Merge branch 'rework/kthreads' into for-linus

drivers/tty/sysrq.c | 2 -
include/linux/console.h | 17 --
include/linux/printk.h | 16 --
kernel/hung_task.c | 11 +-
kernel/panic.c | 6 -
kernel/printk/internal.h | 2 -
kernel/printk/printk.c | 593 +++++---------------------------------------
kernel/printk/printk_safe.c | 32 ---
kernel/rcu/tree_stall.h | 2 -
kernel/reboot.c | 16 +-
kernel/watchdog.c | 4 -
kernel/watchdog_hld.c | 4 -
12 files changed, 65 insertions(+), 640 deletions(-)