2013-08-16 17:19:18

by Tim Gardner

Subject: [PATCH 3.11-rc5 1/2] ALSA: pcm: Add snd_printd_ratelimit()

Direct calls to printk_limit() will emit log noise even when CONFIG_SND_DEBUG is not
defined. Add a wrapper macro around printk_limit() that is conditionally defined by
CONFIG_SND_DEBUG.

Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Pierre-Louis Bossart <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Yacine Belkadi <[email protected]>
Signed-off-by: Tim Gardner <[email protected]>
---

checkpatch is moaning about the use of printk_ratelimit(), but
printk_ratelimited() seems like overkill for a debug feature.

WARNING: Prefer printk_ratelimited or pr_<level>_ratelimited to printk_ratelimit
#38: FILE: include/sound/core.h:382:
+#define snd_printd_ratelimit() printk_ratelimit()

include/sound/core.h | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/include/sound/core.h b/include/sound/core.h
index c586617..2a14f1f 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -27,6 +27,7 @@
#include <linux/rwsem.h> /* struct rw_semaphore */
#include <linux/pm.h> /* pm_message_t */
#include <linux/stringify.h>
+#include <linux/printk.h>

/* number of supported soundcards */
#ifdef CONFIG_SND_DYNAMIC_MINORS
@@ -376,6 +377,11 @@ void __snd_printk(unsigned int level, const char *file, int line,
#define snd_BUG() WARN(1, "BUG?\n")

/**
+ * Suppress high rates of output when CONFIG_SND_DEBUG is enabled.
+ */
+#define snd_printd_ratelimit() printk_ratelimit()
+
+/**
* snd_BUG_ON - debugging check macro
* @cond: condition to evaluate
*
@@ -398,6 +404,8 @@ static inline void _snd_printd(int level, const char *format, ...) {}
unlikely(__ret_warn_on); \
})

+static inline bool snd_printd_ratelimit(void) { return false; }
+
#endif /* CONFIG_SND_DEBUG */

#ifdef CONFIG_SND_DEBUG_VERBOSE
--
1.7.9.5

2013-08-16 17:19:31

by Tim Gardner

Subject: [PATCH 3.11-rc5 2/2] ALSA: pcm: Use snd_printd_ratelimit()

The use of snd_printd_ratelimit() supresses superfluous output from
printk_ratelimit() when CONFIG_SND_DEBUG is not defined. For example,

[ 43.753692] snd_pcm_update_hw_ptr0: 26 callbacks suppressed
[ 48.822131] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 53.894953] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 58.997761] snd_pcm_update_hw_ptr0: 25 callbacks suppressed
[ 64.100952] snd_pcm_update_hw_ptr0: 25 callbacks suppressed

fills the log even when no debug output is actually produced.

Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Pierre-Louis Bossart <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Yacine Belkadi <[email protected]>
Signed-off-by: Tim Gardner <[email protected]>
---
sound/core/pcm_lib.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 82bb029..6e03b46 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -184,7 +184,7 @@ static void xrun(struct snd_pcm_substream *substream)
do { \
if (xrun_debug(substream, XRUN_DEBUG_BASIC)) { \
xrun_log_show(substream); \
- if (printk_ratelimit()) { \
+ if (snd_printd_ratelimit()) { \
snd_printd("PCM: " fmt, ##args); \
} \
dump_stack_on_xrun(substream); \
@@ -342,7 +342,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream,
return -EPIPE;
}
if (pos >= runtime->buffer_size) {
- if (printk_ratelimit()) {
+ if (snd_printd_ratelimit()) {
char name[16];
snd_pcm_debug_name(substream, name, sizeof(name));
xrun_log_show(substream);
--
1.7.9.5

2013-08-19 13:47:52

by Takashi Iwai

Subject: Re: [PATCH 3.11-rc5 1/2] ALSA: pcm: Add snd_printd_ratelimit()

At Fri, 16 Aug 2013 11:18:59 -0600,
Tim Gardner wrote:
>
> Direct calls to printk_limit() will emit log noise even when CONFIG_SND_DEBUG is not
> defined. Add a wrapper macro around printk_limit() that is conditionally defined by
> CONFIG_SND_DEBUG.
>
> Cc: Jaroslav Kysela <[email protected]>
> Cc: Takashi Iwai <[email protected]>
> Cc: Pierre-Louis Bossart <[email protected]>
> Cc: Lars-Peter Clausen <[email protected]>
> Cc: Yacine Belkadi <[email protected]>
> Signed-off-by: Tim Gardner <[email protected]>
> ---
>
> checkpatch is moaning about the use of printk_ratelimit(), but
> printk_ratelimited() seems like overkill for a debug feature.
>
> WARNING: Prefer printk_ratelimited or pr_<level>_ratelimited to printk_ratelimit
> #38: FILE: include/sound/core.h:382:
> +#define snd_printd_ratelimit() printk_ratelimit()

Thanks, applied both patches now.
But it's no real bug, so I postpone this for 3.12 inclusion.


Takashi


>
> include/sound/core.h | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/include/sound/core.h b/include/sound/core.h
> index c586617..2a14f1f 100644
> --- a/include/sound/core.h
> +++ b/include/sound/core.h
> @@ -27,6 +27,7 @@
> #include <linux/rwsem.h> /* struct rw_semaphore */
> #include <linux/pm.h> /* pm_message_t */
> #include <linux/stringify.h>
> +#include <linux/printk.h>
>
> /* number of supported soundcards */
> #ifdef CONFIG_SND_DYNAMIC_MINORS
> @@ -376,6 +377,11 @@ void __snd_printk(unsigned int level, const char *file, int line,
> #define snd_BUG() WARN(1, "BUG?\n")
>
> /**
> + * Suppress high rates of output when CONFIG_SND_DEBUG is enabled.
> + */
> +#define snd_printd_ratelimit() printk_ratelimit()
> +
> +/**
> * snd_BUG_ON - debugging check macro
> * @cond: condition to evaluate
> *
> @@ -398,6 +404,8 @@ static inline void _snd_printd(int level, const char *format, ...) {}
> unlikely(__ret_warn_on); \
> })
>
> +static inline bool snd_printd_ratelimit(void) { return false; }
> +
> #endif /* CONFIG_SND_DEBUG */
>
> #ifdef CONFIG_SND_DEBUG_VERBOSE
> --
> 1.7.9.5
>