From: Dave Young Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some serious complaining of kernel, we need repeat the warnings, so here I isolate the ratelimit part of printk.c to a standalone file. Signed-off-by: Dave Young Acked-by: Paul E. McKenney Tested-by: Paul E. McKenney Signed-off-by: Andrew Morton --- include/linux/kernel.h | 1 kernel/printk.c | 26 ------------------- lib/Makefile | 2 - lib/ratelimit.c | 51 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 54 insertions(+), 26 deletions(-) diff -puN include/linux/kernel.h~isolate-ratelimit-from-printkc-for-other-use include/linux/kernel.h --- a/include/linux/kernel.h~isolate-ratelimit-from-printkc-for-other-use +++ a/include/linux/kernel.h @@ -188,6 +188,7 @@ extern int log_buf_copy(char *dest, int extern int printk_ratelimit_jiffies; extern int printk_ratelimit_burst; extern int printk_ratelimit(void); +extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst); extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst); extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, unsigned int interval_msec); diff -puN kernel/printk.c~isolate-ratelimit-from-printkc-for-other-use kernel/printk.c --- a/kernel/printk.c~isolate-ratelimit-from-printkc-for-other-use +++ a/kernel/printk.c @@ -1290,31 +1290,7 @@ void tty_write_message(struct tty_struct */ int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) { - static DEFINE_SPINLOCK(ratelimit_lock); - static unsigned toks = 10 * 5 * HZ; - static unsigned long last_msg; - static int missed; - unsigned long flags; - unsigned long now = jiffies; - - spin_lock_irqsave(&ratelimit_lock, flags); - toks += now - last_msg; - last_msg = now; - if (toks > (ratelimit_burst * ratelimit_jiffies)) - toks = ratelimit_burst * ratelimit_jiffies; - if (toks >= ratelimit_jiffies) { - int lost = missed; - - missed = 0; - toks -= ratelimit_jiffies; - spin_unlock_irqrestore(&ratelimit_lock, flags); - if (lost) - printk(KERN_WARNING "printk: %d messages suppressed.\n", lost); - return 1; - } - missed++; - spin_unlock_irqrestore(&ratelimit_lock, flags); - return 0; + return __ratelimit(ratelimit_jiffies, ratelimit_burst); } EXPORT_SYMBOL(__printk_ratelimit); diff -puN lib/Makefile~isolate-ratelimit-from-printkc-for-other-use lib/Makefile --- a/lib/Makefile~isolate-ratelimit-from-printkc-for-other-use +++ a/lib/Makefile @@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmd rbtree.o radix-tree.o dump_stack.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ - proportions.o prio_heap.o + proportions.o prio_heap.o ratelimit.o ifdef CONFIG_FTRACE # Do not profile string.o, since it may be used in early boot or vdso diff -puN /dev/null lib/ratelimit.c --- /dev/null +++ a/lib/ratelimit.c @@ -0,0 +1,51 @@ +/* + * ratelimit.c - Do something with rate limit. + * + * Isolated from kernel/printk.c by Dave Young + * + * This file is released under the GPLv2. + * + */ + +#include +#include +#include + +/* + * __ratelimit - rate limiting + * @ratelimit_jiffies: minimum time in jiffies between too callbacks + * @ratelimit_burst: number of callbacks we do before ratelimiting + * + * This enforces a rate limit: not more than @ratelimit_burst callbacks + * in every ratelimit_jiffies + */ +int __ratelimit(int ratelimit_jiffies, int ratelimit_burst) +{ + static DEFINE_SPINLOCK(ratelimit_lock); + static unsigned toks = 10 * 5 * HZ; + static unsigned long last_msg; + static int missed; + unsigned long flags; + unsigned long now = jiffies; + + spin_lock_irqsave(&ratelimit_lock, flags); + toks += now - last_msg; + last_msg = now; + if (toks > (ratelimit_burst * ratelimit_jiffies)) + toks = ratelimit_burst * ratelimit_jiffies; + if (toks >= ratelimit_jiffies) { + int lost = missed; + + missed = 0; + toks -= ratelimit_jiffies; + spin_unlock_irqrestore(&ratelimit_lock, flags); + if (lost) + printk(KERN_WARNING "__ratelimit: %d messages" + " suppressed.\n", lost); + return 1; + } + missed++; + spin_unlock_irqrestore(&ratelimit_lock, flags); + return 0; +} +EXPORT_SYMBOL(__ratelimit); _