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-rw-r--r--lib/ratelimit.c56
1 files changed, 31 insertions, 25 deletions
diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 485e3040dcd4..26187edcc7ea 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -3,6 +3,9 @@
3 * 3 *
4 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com> 4 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
5 * 5 *
6 * 2008-05-01 rewrite the function and use a ratelimit_state data struct as
7 * parameter. Now every user can use their own standalone ratelimit_state.
8 *
6 * This file is released under the GPLv2. 9 * This file is released under the GPLv2.
7 * 10 *
8 */ 11 */
@@ -11,41 +14,44 @@
11#include <linux/jiffies.h> 14#include <linux/jiffies.h>
12#include <linux/module.h> 15#include <linux/module.h>
13 16
17static DEFINE_SPINLOCK(ratelimit_lock);
18
14/* 19/*
15 * __ratelimit - rate limiting 20 * __ratelimit - rate limiting
16 * @ratelimit_jiffies: minimum time in jiffies between two callbacks 21 * @rs: ratelimit_state data
17 * @ratelimit_burst: number of callbacks we do before ratelimiting
18 * 22 *
19 * This enforces a rate limit: not more than @ratelimit_burst callbacks 23 * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
20 * in every ratelimit_jiffies 24 * in every @rs->ratelimit_jiffies
21 */ 25 */
22int __ratelimit(int ratelimit_jiffies, int ratelimit_burst) 26int __ratelimit(struct ratelimit_state *rs)
23{ 27{
24 static DEFINE_SPINLOCK(ratelimit_lock);
25 static unsigned toks = 10 * 5 * HZ;
26 static unsigned long last_msg;
27 static int missed;
28 unsigned long flags; 28 unsigned long flags;
29 unsigned long now = jiffies;
30 29
31 spin_lock_irqsave(&ratelimit_lock, flags); 30 if (!rs->interval)
32 toks += now - last_msg;
33 last_msg = now;
34 if (toks > (ratelimit_burst * ratelimit_jiffies))
35 toks = ratelimit_burst * ratelimit_jiffies;
36 if (toks >= ratelimit_jiffies) {
37 int lost = missed;
38
39 missed = 0;
40 toks -= ratelimit_jiffies;
41 spin_unlock_irqrestore(&ratelimit_lock, flags);
42 if (lost)
43 printk(KERN_WARNING "%s: %d messages suppressed\n",
44 __func__, lost);
45 return 1; 31 return 1;
32
33 spin_lock_irqsave(&ratelimit_lock, flags);
34 if (!rs->begin)
35 rs->begin = jiffies;
36
37 if (time_is_before_jiffies(rs->begin + rs->interval)) {
38 if (rs->missed)
39 printk(KERN_WARNING "%s: %d callbacks suppressed\n",
40 __func__, rs->missed);
41 rs->begin = 0;
42 rs->printed = 0;
43 rs->missed = 0;
46 } 44 }
47 missed++; 45 if (rs->burst && rs->burst > rs->printed)
46 goto print;
47
48 rs->missed++;
48 spin_unlock_irqrestore(&ratelimit_lock, flags); 49 spin_unlock_irqrestore(&ratelimit_lock, flags);
49 return 0; 50 return 0;
51
52print:
53 rs->printed++;
54 spin_unlock_irqrestore(&ratelimit_lock, flags);
55 return 1;
50} 56}
51EXPORT_SYMBOL(__ratelimit); 57EXPORT_SYMBOL(__ratelimit);