Merge git://git.infradead.org/~dwmw2/random-2.6

[pandora-kernel.git] / lib / ratelimit.c

diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 485e304..3513667 100644 (file)
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -3,6 +3,9 @@
  *
  * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
  *
+ * 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.
  *
  */
@@ -11,41 +14,43 @@
 #include <linux/jiffies.h>
 #include <linux/module.h>
 
+static DEFINE_SPINLOCK(ratelimit_lock);
+static unsigned long flags;
+
 /*
  * __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
  *
- * This enforces a rate limit: not more than @ratelimit_burst callbacks
- * in every ratelimit_jiffies
+ * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
+ * in every @rs->ratelimit_jiffies
  */
-int __ratelimit(int ratelimit_jiffies, int ratelimit_burst)
+int __ratelimit(struct ratelimit_state *rs)
 {
-       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;
+       if (!rs->interval)
+               return 1;
 
        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;
+       if (!rs->begin)
+               rs->begin = jiffies;
 
-               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;
+       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++;
+       if (rs->burst && rs->burst > rs->printed)
+               goto print;
+
+       rs->missed++;
        spin_unlock_irqrestore(&ratelimit_lock, flags);
        return 0;
+
+print:
+       rs->printed++;
+       spin_unlock_irqrestore(&ratelimit_lock, flags);
+       return 1;
 }
 EXPORT_SYMBOL(__ratelimit);