isolate ratelimit from printk.c for other use

Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file.  For some
serious complaining of kernel, we need repeat the warnings, so here I isolate
the ratelimit part of printk.c to a standalone file.

Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 25 deletions

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)
  */
 int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst)
 {
-        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;
-
-        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 "printk: %d messages suppressed.\n", lost);
-                return 1;
-        }
-        missed++;
-        spin_unlock_irqrestore(&ratelimit_lock, flags);
-        return 0;
+        return __ratelimit(ratelimit_jiffies, ratelimit_burst);
 }
 EXPORT_SYMBOL(__printk_ratelimit);