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Subject[PATCH 0/3] clear_warn_once: add timed interval resetting
The existing clear_warn_once functionality is currently a manually
issued state reset via the file /sys/kernel/debug/clear_warn_once when
debugfs is mounted. The idea being that a developer would be running
some tests, like LTP or similar, and want to check reproducibility
without having to reboot.

But you currently can't make use of clear_warn_once unless you've got
debugfs enabled and mounted - which may not be desired by some people
in some deployment situations.

The functionality added here allows for periodic resets in addition to
the one-shot reset it already had. Then we allow for a boot-time setting
of the periodic resets so it can be used even when debugfs isn't mounted.

By having a periodic reset, we also open the door for having the various
"once" functions act as long period ratelimited messages, where a sysadmin
can pick an hour or a day reset if they are facing an issue and are
wondering "did this just happen once, or am I only being informed once?"

Tested with DEBUG_FS_ALLOW_ALL and DEBUG_FS_ALLOW_NONE on an otherwise


Cc: Andi Kleen <>
Cc: Petr Mladek <>
Cc: Sergey Senozhatsky <>
Cc: Steven Rostedt <>
Cc: John Ogness <>

Paul Gortmaker (3):
clear_warn_once: expand debugfs to include read support
clear_warn_once: bind a timer to written reset value
clear_warn_once: add a warn_once_reset= boot parameter

.../admin-guide/clearing-warn-once.rst | 9 +++
.../admin-guide/kernel-parameters.txt | 8 ++
kernel/panic.c | 78 +++++++++++++++++--
3 files changed, 90 insertions(+), 5 deletions(-)


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