printk: Tie printk_once / printk_deferred_once into .data.once for reset
authorPaul Gortmaker <paul.gortmaker@windriver.com>
Sat, 13 Apr 2019 02:11:31 +0000 (22:11 -0400)
committerPetr Mladek <pmladek@suse.com>
Mon, 15 Apr 2019 08:23:53 +0000 (10:23 +0200)
commit3ec25826ae33618a03c28235af8d62e8a7f7f15f
tree142911824661921ae29ccc96d894c2e6e3782dc8
parent2821fd0c2be0c4e513b1622d86df9170ef62a6d4
printk: Tie printk_once / printk_deferred_once into .data.once for reset

In commit b1fca27d384e ("kernel debug: support resetting WARN*_ONCE")
we got the opportunity to reset state on the one shot messages,
without having to reboot.

However printk_once (printk_deferred_once) live in a different file
and didn't get the same kind of update/conversion, so they remain
unconditionally one shot, until the system is rebooted.

For example, we currently have:

  sched/rt.c: printk_deferred_once("sched: RT throttling activated\n");

..which could reasonably be tripped as someone is testing and tuning
a new system/workload and their task placements.  For consistency, and
to avoid reboots in the same vein as the original commit, we make these
two instances of _once the same as the WARN*_ONCE instances are.

Link: http://lkml.kernel.org/r/1555121491-31213-1-git-send-email-paul.gortmaker@windriver.com
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Documentation/clearing-warn-once.txt
include/linux/printk.h