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-rw-r--r--include/linux/kernel.h1
-rw-r--r--kernel/printk.c26
-rw-r--r--lib/Makefile2
-rw-r--r--lib/ratelimit.c51
4 files changed, 54 insertions, 26 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 28caa53dd1f7..ad5d05efcd1a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -188,6 +188,7 @@ extern int log_buf_copy(char *dest, int idx, int len);
188extern int printk_ratelimit_jiffies; 188extern int printk_ratelimit_jiffies;
189extern int printk_ratelimit_burst; 189extern int printk_ratelimit_burst;
190extern int printk_ratelimit(void); 190extern int printk_ratelimit(void);
191extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);
191extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst); 192extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
192extern bool printk_timed_ratelimit(unsigned long *caller_jiffies, 193extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
193 unsigned int interval_msec); 194 unsigned int interval_msec);
diff --git a/kernel/printk.c b/kernel/printk.c
index bdd4ea8c3f2b..d3f9c0f788bf 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1287,31 +1287,7 @@ void tty_write_message(struct tty_struct *tty, char *msg)
1287 */ 1287 */
1288int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) 1288int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst)
1289{ 1289{
1290 static DEFINE_SPINLOCK(ratelimit_lock); 1290 return __ratelimit(ratelimit_jiffies, ratelimit_burst);
1291 static unsigned toks = 10 * 5 * HZ;
1292 static unsigned long last_msg;
1293 static int missed;
1294 unsigned long flags;
1295 unsigned long now = jiffies;
1296
1297 spin_lock_irqsave(&ratelimit_lock, flags);
1298 toks += now - last_msg;
1299 last_msg = now;
1300 if (toks > (ratelimit_burst * ratelimit_jiffies))
1301 toks = ratelimit_burst * ratelimit_jiffies;
1302 if (toks >= ratelimit_jiffies) {
1303 int lost = missed;
1304
1305 missed = 0;
1306 toks -= ratelimit_jiffies;
1307 spin_unlock_irqrestore(&ratelimit_lock, flags);
1308 if (lost)
1309 printk(KERN_WARNING "printk: %d messages suppressed.\n", lost);
1310 return 1;
1311 }
1312 missed++;
1313 spin_unlock_irqrestore(&ratelimit_lock, flags);
1314 return 0;
1315} 1291}
1316EXPORT_SYMBOL(__printk_ratelimit); 1292EXPORT_SYMBOL(__printk_ratelimit);
1317 1293
diff --git a/lib/Makefile b/lib/Makefile
index 2d7001b7f5a4..0ae4eb047aac 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
6 rbtree.o radix-tree.o dump_stack.o \ 6 rbtree.o radix-tree.o dump_stack.o \
7 idr.o int_sqrt.o extable.o prio_tree.o \ 7 idr.o int_sqrt.o extable.o prio_tree.o \
8 sha1.o irq_regs.o reciprocal_div.o argv_split.o \ 8 sha1.o irq_regs.o reciprocal_div.o argv_split.o \
9 proportions.o prio_heap.o 9 proportions.o prio_heap.o ratelimit.o
10 10
11lib-$(CONFIG_MMU) += ioremap.o 11lib-$(CONFIG_MMU) += ioremap.o
12lib-$(CONFIG_SMP) += cpumask.o 12lib-$(CONFIG_SMP) += cpumask.o
diff --git a/lib/ratelimit.c b/lib/ratelimit.c
new file mode 100644
index 000000000000..485e3040dcd4
--- /dev/null
+++ b/lib/ratelimit.c
@@ -0,0 +1,51 @@
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 * This file is released under the GPLv2.
7 *
8 */
9
10#include <linux/kernel.h>
11#include <linux/jiffies.h>
12#include <linux/module.h>
13
14/*
15 * __ratelimit - rate limiting
16 * @ratelimit_jiffies: minimum time in jiffies between two callbacks
17 * @ratelimit_burst: number of callbacks we do before ratelimiting
18 *
19 * This enforces a rate limit: not more than @ratelimit_burst callbacks
20 * in every ratelimit_jiffies
21 */
22int __ratelimit(int ratelimit_jiffies, int ratelimit_burst)
23{
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;
29 unsigned long now = jiffies;
30
31 spin_lock_irqsave(&ratelimit_lock, flags);
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;
46 }
47 missed++;
48 spin_unlock_irqrestore(&ratelimit_lock, flags);
49 return 0;
50}
51EXPORT_SYMBOL(__ratelimit);