diff options
Diffstat (limited to 'lib/ratelimit.c')
-rw-r--r-- | lib/ratelimit.c | 54 |
1 files changed, 32 insertions, 22 deletions
diff --git a/lib/ratelimit.c b/lib/ratelimit.c index 26187ed..027a03f 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -7,51 +7,61 @@ * parameter. Now every user can use their own standalone ratelimit_state. * * This file is released under the GPLv2. - * */ -#include <linux/kernel.h> +#include <linux/ratelimit.h> #include <linux/jiffies.h> #include <linux/module.h> -static DEFINE_SPINLOCK(ratelimit_lock); - /* * __ratelimit - rate limiting * @rs: ratelimit_state data + * @func: name of calling function + * + * This enforces a rate limit: not more than @rs->burst callbacks + * in every @rs->interval * - * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks - * in every @rs->ratelimit_jiffies + * RETURNS: + * 0 means callbacks will be suppressed. + * 1 means go ahead and do it. */ -int __ratelimit(struct ratelimit_state *rs) +int ___ratelimit(struct ratelimit_state *rs, const char *func) { unsigned long flags; + int ret; if (!rs->interval) return 1; - spin_lock_irqsave(&ratelimit_lock, flags); + /* + * If we contend on this state's lock then almost + * by definition we are too busy to print a message, + * in addition to the one that will be printed by + * the entity that is holding the lock already: + */ + if (!spin_trylock_irqsave(&rs->lock, flags)) + return 0; + if (!rs->begin) rs->begin = jiffies; if (time_is_before_jiffies(rs->begin + rs->interval)) { if (rs->missed) printk(KERN_WARNING "%s: %d callbacks suppressed\n", - __func__, rs->missed); - rs->begin = 0; + func, rs->missed); + rs->begin = 0; rs->printed = 0; - rs->missed = 0; + rs->missed = 0; } - if (rs->burst && rs->burst > rs->printed) - goto print; - - rs->missed++; - spin_unlock_irqrestore(&ratelimit_lock, flags); - return 0; + if (rs->burst && rs->burst > rs->printed) { + rs->printed++; + ret = 1; + } else { + rs->missed++; + ret = 0; + } + spin_unlock_irqrestore(&rs->lock, flags); -print: - rs->printed++; - spin_unlock_irqrestore(&ratelimit_lock, flags); - return 1; + return ret; } -EXPORT_SYMBOL(__ratelimit); +EXPORT_SYMBOL(___ratelimit); |