[PATCH 0/6] printk: Revert console kthreads for 5.19

From: Petr Mladek
Date: Thu Jun 23 2022 - 10:52:16 EST


We have had several discussions with the other printk developers and
together decided that we would like more time to investigate
the implicit expectations [1] of each and every console driver
because now we are concerned that there may be more hidden implicit
expectations.

We much appreciate the chance to have this in 5.19 release candidates
because the wider user base helped us to get feedback from user cases
and architectures that we were not able to cover. And we see that
the patchset needs some more love.

We are sorry for the inconvenience and thanks a lot for the feedback
and help with debugging and testing.

This patchset reverts only the final patches adding the kthreads and
per-console. It keeps the refactoring of the console_unlock() code
that makes sense on its own.

[1] https://lore.kernel.org/all/YrBdjVwBOVgLfHyb@alley/

PS: I am going to prepare a proper pull request. I just wanted
to send this in advance just in case anyone wants to comment
on it.

Petr Mladek (6):
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"

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(-)

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2.35.3