* This file is released under the GPLv2.
*/
-#include <linux/kernel.h>
+#include <linux/ratelimit.h>
#include <linux/jiffies.h>
#include <linux/module.h>
/*
* __ratelimit - rate limiting
* @rs: ratelimit_state data
+ * @func: name of calling function
*
- * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
- * in every @rs->ratelimit_jiffies
+ * This enforces a rate limit: not more than @rs->burst callbacks
+ * in every @rs->interval
+ *
+ * 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(&rs->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);
+ func, rs->missed);
rs->begin = 0;
rs->printed = 0;
rs->missed = 0;
return ret;
}
-EXPORT_SYMBOL(__ratelimit);
+EXPORT_SYMBOL(___ratelimit);