summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorPaul Gortmaker <paul.gortmaker@windriver.com>2019-04-13 05:11:31 +0300
committerPetr Mladek <pmladek@suse.com>2019-04-15 11:23:53 +0300
commit3ec25826ae33618a03c28235af8d62e8a7f7f15f (patch)
tree142911824661921ae29ccc96d894c2e6e3782dc8
parent2821fd0c2be0c4e513b1622d86df9170ef62a6d4 (diff)
downloadlinux-3ec25826ae33618a03c28235af8d62e8a7f7f15f.tar.xz
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>
-rw-r--r--Documentation/clearing-warn-once.txt2
-rw-r--r--include/linux/printk.h4
2 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/clearing-warn-once.txt b/Documentation/clearing-warn-once.txt
index 5b1f5d547be1..c68598b31428 100644
--- a/Documentation/clearing-warn-once.txt
+++ b/Documentation/clearing-warn-once.txt
@@ -1,5 +1,5 @@
-WARN_ONCE / WARN_ON_ONCE only print a warning once.
+WARN_ONCE / WARN_ON_ONCE / printk_once only emit a message once.
echo 1 > /sys/kernel/debug/clear_warn_once
diff --git a/include/linux/printk.h b/include/linux/printk.h
index d7c77ed1a4cb..84ea4d094af3 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -347,7 +347,7 @@ extern int kptr_restrict;
#ifdef CONFIG_PRINTK
#define printk_once(fmt, ...) \
({ \
- static bool __print_once __read_mostly; \
+ static bool __section(.data.once) __print_once; \
bool __ret_print_once = !__print_once; \
\
if (!__print_once) { \
@@ -358,7 +358,7 @@ extern int kptr_restrict;
})
#define printk_deferred_once(fmt, ...) \
({ \
- static bool __print_once __read_mostly; \
+ static bool __section(.data.once) __print_once; \
bool __ret_print_once = !__print_once; \
\
if (!__print_once) { \