From 5c828713358cb9df8aa174371edcbbb62203a490 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Fri, 23 Oct 2009 14:58:11 +0200 Subject: [PATCH] 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 Cc: Dave Young Cc: Linus Torvalds CC: Andrew Morton LKML-Reference: <200910231458.11832.borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar --- include/linux/kernel.h | 3 ++- include/linux/ratelimit.h | 3 ++- kernel/printk.c | 6 +++--- lib/ratelimit.c | 6 +++--- 4 files changed, 10 insertions(+), 8 deletions(-) diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3305f33201b..21d0d822c71 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 187bc16c1f1..668cf1bef03 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 b997c893cdc..8283dbe15af 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 5551731ae1d..09f5ce1810d 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);