linux/kernel/printk
John Ogness 054c22bd78 printk: flush consoles before checking progress
Commit 9e70a5e109 ("printk: Add per-console suspended state")
removed console lock usage during resume and replaced it with
the clearly defined console_list_lock and srcu mechanisms.

However, the console lock usage had an important side-effect
of flushing the consoles. After its removal, consoles were no
longer flushed before checking their progress.

Add the console_lock/console_unlock dance to the beginning
of __pr_flush() to actually flush the consoles before checking
their progress. Also add comments to clarify this additional
usage of the console lock.

Note that console_unlock() does not guarantee flushing all messages
since the commit dbdda842fe ("printk: Add console owner and waiter
logic to load balance console writes").

Reported-by: Todd Brandt <todd.e.brandt@intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217955
Fixes: 9e70a5e109 ("printk: Add per-console suspended state")
Co-developed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20231006082151.6969-2-pmladek@suse.com
2023-10-09 10:15:04 +02:00
..
braille.c printk: Replace strncmp() with str_has_prefix() 2019-08-16 09:54:08 +02:00
braille.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
console_cmdline.h printk: Fix preferred console selection with multiple matches 2020-02-18 09:34:42 +01:00
index.c kernel/printk/index.c: fix memory leak with using debugfs_lookup() 2023-02-03 10:42:02 +01:00
internal.h printk: Rename abandon_console_lock_in_panic() to other_cpu_in_panic() 2023-07-20 13:06:22 +02:00
Makefile printk: move printk sysctl to printk/sysctl.c 2022-01-22 08:33:35 +02:00
printk_ringbuffer.c printk: fix a typo of comment 2022-11-22 12:10:15 +01:00
printk_ringbuffer.h printk: ringbuffer: Improve prb_next_seq() performance 2022-01-26 16:00:32 +01:00
printk_safe.c printk: Consolidate console deferred printing 2023-07-20 13:06:22 +02:00
printk.c printk: flush consoles before checking progress 2023-10-09 10:15:04 +02:00
sysctl.c printk: Fix incorrect __user type in proc_dointvec_minmax_sysadmin() 2022-02-03 11:27:38 -08:00