1 files changed, 47 insertions, 31 deletions

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 485e3040dcd..40e03ea2a96 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -3,49 +3,65 @@
  *
  * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
  *
- * This file is released under the GPLv2.
+ * 2008-05-01 rewrite the function and use a ratelimit_state data struct as
+ * 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>
+#include <linux/export.h>
 
 /*
  * __ratelimit - rate limiting
- * @ratelimit_jiffies: minimum time in jiffies between two callbacks
- * @ratelimit_burst: number of callbacks we do before ratelimiting
+ * @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 @ratelimit_burst callbacks
- * in every ratelimit_jiffies
+ * RETURNS:
+ * 0 means callbacks will be suppressed.
+ * 1 means go ahead and do it.
  */
-int __ratelimit(int ratelimit_jiffies, int ratelimit_burst)
+int ___ratelimit(struct ratelimit_state *rs, const char *func)
 {
-	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;
+	int ret;
 
-	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);
+	if (!rs->interval)
 		return 1;
+
+	/*
+	 * 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 (!raw_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;
+		rs->printed = 0;
+		rs->missed  = 0;
 	}
-	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;
+	}
+	raw_spin_unlock_irqrestore(&rs->lock, flags);
+
+	return ret;
 }
-EXPORT_SYMBOL(__ratelimit);
+EXPORT_SYMBOL(___ratelimit);