viafb: Only establish i2c busses on ports that always had them
[deliverable/linux.git] / lib / ratelimit.c
1 /*
2 * ratelimit.c - Do something with rate limit.
3 *
4 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
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 *
9 * This file is released under the GPLv2.
10 */
11
12 #include <linux/ratelimit.h>
13 #include <linux/jiffies.h>
14 #include <linux/module.h>
15
16 /*
17 * __ratelimit - rate limiting
18 * @rs: ratelimit_state data
19 *
20 * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
21 * in every @rs->ratelimit_jiffies
22 */
23 int ___ratelimit(struct ratelimit_state *rs, const char *func)
24 {
25 unsigned long flags;
26 int ret;
27
28 if (!rs->interval)
29 return 1;
30
31 /*
32 * If we contend on this state's lock then almost
33 * by definition we are too busy to print a message,
34 * in addition to the one that will be printed by
35 * the entity that is holding the lock already:
36 */
37 if (!spin_trylock_irqsave(&rs->lock, flags))
38 return 1;
39
40 if (!rs->begin)
41 rs->begin = jiffies;
42
43 if (time_is_before_jiffies(rs->begin + rs->interval)) {
44 if (rs->missed)
45 printk(KERN_WARNING "%s: %d callbacks suppressed\n",
46 func, rs->missed);
47 rs->begin = 0;
48 rs->printed = 0;
49 rs->missed = 0;
50 }
51 if (rs->burst && rs->burst > rs->printed) {
52 rs->printed++;
53 ret = 1;
54 } else {
55 rs->missed++;
56 ret = 0;
57 }
58 spin_unlock_irqrestore(&rs->lock, flags);
59
60 return ret;
61 }
62 EXPORT_SYMBOL(___ratelimit);
This page took 0.036901 seconds and 5 git commands to generate.