diff options
| -rw-r--r-- | include/linux/kernel.h | 1 | ||||
| -rw-r--r-- | kernel/printk.c | 26 | ||||
| -rw-r--r-- | lib/Makefile | 2 | ||||
| -rw-r--r-- | lib/ratelimit.c | 51 |
4 files changed, 54 insertions, 26 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 28caa53..ad5d05e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -188,6 +188,7 @@ extern int log_buf_copy(char *dest, int idx, int len); 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 --git a/kernel/printk.c b/kernel/printk.c index bdd4ea8..d3f9c0f 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1287,31 +1287,7 @@ void tty_write_message(struct tty_struct *tty, char *msg) */ 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 --git a/lib/Makefile b/lib/Makefile index 2d7001b..0ae4eb0 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ 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 lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o diff --git a/lib/ratelimit.c b/lib/ratelimit.c new file mode 100644 index 0000000..485e304 --- /dev/null +++ b/lib/ratelimit.c @@ -0,0 +1,51 @@ +/* + * ratelimit.c - Do something with rate limit. + * + * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com> + * + * This file is released under the GPLv2. + * + */ + +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/module.h> + +/* + * __ratelimit - rate limiting + * @ratelimit_jiffies: minimum time in jiffies between two 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 "%s: %d messages suppressed\n", + __func__, lost); + return 1; + } + missed++; + spin_unlock_irqrestore(&ratelimit_lock, flags); + return 0; +} +EXPORT_SYMBOL(__ratelimit); |