diff options
| author | Joe Perches <joe@perches.com> | 2013-10-26 20:41:53 -0700 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-05-05 11:17:02 +0200 |
| commit | ec44c106c1641a532faaed93a7d26d4b3e90cc25 (patch) | |
| tree | 412450819b4c08cfe366b15ef7c307a892f4be8a | |
| parent | 1b667c7507f5a34d4f4d2a18c63ebba0139a6d70 (diff) | |
printk: pr_debug_ratelimited: check state first to reduce "callbacks suppressed" messages
commit 29fc2bc75393864bbc9b90a7a13a0d0e11c6f41e upstream.
pr_debug_ratelimited should be coded similarly to dev_dbg_ratelimited
to reduce the "callbacks suppressed" messages.
Add #include <linux/dynamic_debug.h> to printk.h. Unfortunately, this
new #include must be after the prototype/declaration of function printk.
It may be better to split out these _ratelimited declarations into
a separate file one day.
Any use of these pr_<foo>_ratelimited functions must also have another
specific #include <ratelimited.h>. Most users have this done indirectly
via #include <linux/kernel.h>
printk.h may not #include <linux/ratelimit.h> as it causes circular
dependencies and compilation failures.
Signed-off-by: Joe Perches <joe@perches.com>
Tested-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
| -rw-r--r-- | include/linux/printk.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/include/linux/printk.h b/include/linux/printk.h index e6131a782481..694925837a16 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -233,6 +233,8 @@ extern asmlinkage void dump_stack(void) __cold; no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) #endif +#include <linux/dynamic_debug.h> + /* If you are writing a driver, please use dev_dbg instead */ #if defined(CONFIG_DYNAMIC_DEBUG) /* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */ @@ -343,7 +345,19 @@ extern asmlinkage void dump_stack(void) __cold; #endif /* If you are writing a driver, please use dev_dbg instead */ -#if defined(DEBUG) +#if defined(CONFIG_DYNAMIC_DEBUG) +/* descriptor check is first to prevent flooding with "callbacks suppressed" */ +#define pr_debug_ratelimited(fmt, ...) \ +do { \ + static DEFINE_RATELIMIT_STATE(_rs, \ + DEFAULT_RATELIMIT_INTERVAL, \ + DEFAULT_RATELIMIT_BURST); \ + DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \ + if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT) && \ + __ratelimit(&_rs)) \ + __dynamic_pr_debug(&descriptor, fmt, ##__VA_ARGS__); \ +} while (0) +#elif defined(DEBUG) #define pr_debug_ratelimited(fmt, ...) \ printk_ratelimited(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__) #else |