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authorChristian Borntraeger <borntraeger@de.ibm.com>2009-10-23 14:58:11 +0200
committerIngo Molnar <mingo@elte.hu>2009-10-23 17:26:37 +0200
commit5c828713358cb9df8aa174371edcbbb62203a490 (patch)
treec8aeafba911cb428b5dc46a9e252c337b7c51d17
parent3fff4c42bd0a89869a0eb1e7874cc06ffa4aa0f5 (diff)
downloadlwn-5c828713358cb9df8aa174371edcbbb62203a490.tar.gz
lwn-5c828713358cb9df8aa174371edcbbb62203a490.zip
ratelimit: Make suppressed output messages more useful
Today I got: [39648.224782] Registered led device: iwl-phy0::TX [40676.545099] __ratelimit: 246 callbacks suppressed [40676.545103] abcdef[23675]: segfault at 0 ... as you can see the ratelimit message contains a function prefix. Since this is always __ratelimit, this wont help much. This patch changes __ratelimit and printk_ratelimit to print the function name that calls ratelimit. This will pinpoint the responsible function, as long as not several different places call ratelimit with the same ratelimit state at the same time. In that case we catch only one random function that calls ratelimit after the wait period. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> CC: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <200910231458.11832.borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--include/linux/kernel.h3
-rw-r--r--include/linux/ratelimit.h3
-rw-r--r--kernel/printk.c6
-rw-r--r--lib/ratelimit.c6
4 files changed, 10 insertions, 8 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 3305f33201be..21d0d822c716 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -240,7 +240,8 @@ asmlinkage int vprintk(const char *fmt, va_list args)
asmlinkage int printk(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2))) __cold;
-extern int printk_ratelimit(void);
+extern int __printk_ratelimit(const char *func);
+#define printk_ratelimit() __printk_ratelimit(__func__)
extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msec);
diff --git a/include/linux/ratelimit.h b/include/linux/ratelimit.h
index 187bc16c1f15..668cf1bef030 100644
--- a/include/linux/ratelimit.h
+++ b/include/linux/ratelimit.h
@@ -25,6 +25,7 @@ struct ratelimit_state {
.burst = burst_init, \
}
-extern int __ratelimit(struct ratelimit_state *rs);
+extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
+#define __ratelimit(state) ___ratelimit(state, __func__)
#endif /* _LINUX_RATELIMIT_H */
diff --git a/kernel/printk.c b/kernel/printk.c
index b997c893cdcf..8283dbe15af4 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1364,11 +1364,11 @@ late_initcall(disable_boot_consoles);
*/
DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10);
-int printk_ratelimit(void)
+int __printk_ratelimit(const char *func)
{
- return __ratelimit(&printk_ratelimit_state);
+ return ___ratelimit(&printk_ratelimit_state, func);
}
-EXPORT_SYMBOL(printk_ratelimit);
+EXPORT_SYMBOL(__printk_ratelimit);
/**
* printk_timed_ratelimit - caller-controlled printk ratelimiting
diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 5551731ae1d4..09f5ce1810dc 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -20,7 +20,7 @@
* This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
* in every @rs->ratelimit_jiffies
*/
-int __ratelimit(struct ratelimit_state *rs)
+int ___ratelimit(struct ratelimit_state *rs, const char *func)
{
unsigned long flags;
int ret;
@@ -43,7 +43,7 @@ int __ratelimit(struct ratelimit_state *rs)
if (time_is_before_jiffies(rs->begin + rs->interval)) {
if (rs->missed)
printk(KERN_WARNING "%s: %d callbacks suppressed\n",
- __func__, rs->missed);
+ func, rs->missed);
rs->begin = 0;
rs->printed = 0;
rs->missed = 0;
@@ -59,4 +59,4 @@ int __ratelimit(struct ratelimit_state *rs)
return ret;
}
-EXPORT_SYMBOL(__ratelimit);
+EXPORT_SYMBOL(___ratelimit);