Re: [PATCH 1/1] driver-core: Shut up dev_dbg_reatelimited() withoutDEBUG

From: Antti Palosaari
Date: Mon Aug 20 2012 - 17:29:48 EST


On 08/20/2012 02:14 PM, Hiroshi Doyu wrote:
Hi Antti,

Antti Palosaari <crope@xxxxxx> wrote @ Sat, 18 Aug 2012 02:11:56 +0200:

On 08/17/2012 09:04 AM, Hiroshi Doyu wrote:
dev_dbg_reatelimited() without DEBUG printed "217078 callbacks
suppressed". This shouldn't print anything without DEBUG.

Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
Reported-by: Antti Palosaari <crope@xxxxxx>
---
include/linux/device.h | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index eb945e1..d4dc26e 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -962,9 +962,13 @@ do { \
dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
#define dev_info_ratelimited(dev, fmt, ...) \
dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
+#if defined(DEBUG)
#define dev_dbg_ratelimited(dev, fmt, ...) \
dev_level_ratelimited(dev_dbg, dev, fmt, ##__VA_ARGS__)
-
+#else
+#define dev_dbg_ratelimited(dev, fmt, ...) \
+ no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
+#endif
/*
* Stupid hackaround for existing uses of non-printk uses dev_info
*


NACK. I don't think that's correct behavior. After that patch it kills
all output of dev_dbg_ratelimited(). If I use dynamic debugs and order
debugs, I expect to see debugs as earlier.

You are right. I attached the update patch, just moving *_ratelimited
functions after dev_dbg() definitions.

With DEBUG defined/undefined in your "test.ko", it works fine. With
CONFIG_DYNAMIC_DEBUG, it works with "+p", but with "-p", still
"..callbacks suppressed" is printed.

I am using dynamic debugs and behavior is now just same as it was when reported that bug. OK, likely for static debug it is now correct.

$ insmod test.ko
$ echo -n 'module test +p' > /sys/kernel/debug/dynamic_debug/control"
$ rmmod test
$ dmesg | tail -15
<7>[ 69.047192] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 69.047233] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 69.047275] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<4>[ 75.057045] print_dev_dbg_ratelimited: 90 callbacks suppressed
<7>[ 75.063595] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.063796] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.063970] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064137] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064307] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064472] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064640] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064806] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.064972] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<7>[ 75.065137] (NULL device *): print_dev_dbg_ratelimited: dev_dbg_ratelimited()
<6>[ 75.065510] test module unloaded!

$ insmod test.ko
$ echo -n 'module test -p' > /sys/kernel/debug/dynamic_debug/control"
$ rmmod test
$ dmesg
...
<6>[ 82.715925] test module loaded!
<6>[ 82.795642] dynamic_debug:ddebug_exec_queries: processed 1 queries, with 1 matches, 0 errs
<4>[ 88.892096] print_dev_dbg_ratelimited: 90 callbacks suppressed
<6>[ 88.898397] test module unloaded!

Any suggestion to control "... callbacks suppressed" with
CONFIG_DYNAMIC_DEBUG would be appreciated.

Is it Joe Perches who has added these Kernel dynamic pr_ and dev_ debugging? Maybe he has proper solution that fixes ratelimit for dynamic debugging too.

regards
Antti


From 5b33751f89c2e91ee734325e6d73ed7e1c6d4b02 Mon Sep 17 00:00:00 2001
From: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
Date: Mon, 20 Aug 2012 13:49:19 +0300
Subject: [PATCH 1/1] driver-core: Shut up dev_dbg_reatelimited() without
DEBUG

dev_dbg_reatelimited() without DEBUG printed "217078 callbacks
suppressed". This shouldn't print anything without DEBUG.

With CONFIG_DYNAMIC_DEBUG, the print should be configured as expected.

Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
Reported-by: Antti Palosaari <crope@xxxxxx>
---
include/linux/device.h | 53 ++++++++++++++++++++++++++---------------------
1 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/include/linux/device.h b/include/linux/device.h
index 9648331..763bca4 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -932,6 +932,32 @@ int _dev_info(const struct device *dev, const char *fmt, ...)

#endif

+/*
+ * Stupid hackaround for existing uses of non-printk uses dev_info
+ *
+ * Note that the definition of dev_info below is actually _dev_info
+ * and a macro is used to avoid redefining dev_info
+ */
+
+#define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
+
+#if defined(CONFIG_DYNAMIC_DEBUG)
+#define dev_dbg(dev, format, ...) \
+do { \
+ dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
+} while (0)
+#elif defined(DEBUG)
+#define dev_dbg(dev, format, arg...) \
+ dev_printk(KERN_DEBUG, dev, format, ##arg)
+#else
+#define dev_dbg(dev, format, arg...) \
+({ \
+ if (0) \
+ dev_printk(KERN_DEBUG, dev, format, ##arg); \
+ 0; \
+})
+#endif
+
#define dev_level_ratelimited(dev_level, dev, fmt, ...) \
do { \
static DEFINE_RATELIMIT_STATE(_rs, \
@@ -955,33 +981,12 @@ do { \
dev_level_ratelimited(dev_notice, dev, fmt, ##__VA_ARGS__)
#define dev_info_ratelimited(dev, fmt, ...) \
dev_level_ratelimited(dev_info, dev, fmt, ##__VA_ARGS__)
+#if defined(CONFIG_DYNAMIC_DEBUG) || defined(DEBUG)
#define dev_dbg_ratelimited(dev, fmt, ...) \
dev_level_ratelimited(dev_dbg, dev, fmt, ##__VA_ARGS__)
-
-/*
- * Stupid hackaround for existing uses of non-printk uses dev_info
- *
- * Note that the definition of dev_info below is actually _dev_info
- * and a macro is used to avoid redefining dev_info
- */
-
-#define dev_info(dev, fmt, arg...) _dev_info(dev, fmt, ##arg)
-
-#if defined(CONFIG_DYNAMIC_DEBUG)
-#define dev_dbg(dev, format, ...) \
-do { \
- dynamic_dev_dbg(dev, format, ##__VA_ARGS__); \
-} while (0)
-#elif defined(DEBUG)
-#define dev_dbg(dev, format, arg...) \
- dev_printk(KERN_DEBUG, dev, format, ##arg)
#else
-#define dev_dbg(dev, format, arg...) \
-({ \
- if (0) \
- dev_printk(KERN_DEBUG, dev, format, ##arg); \
- 0; \
-})
+#define dev_dbg_ratelimited(dev, fmt, ...) \
+ no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#endif

#ifdef VERBOSE_DEBUG



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