Commit 5f97a5a8 authored by Dave Young's avatar Dave Young Committed by Linus Torvalds
Browse files

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: default avatarDave Young <hidave.darkstar@gmail.com>
Acked-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 762873c2

include/linux/kernel.h

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ extern int log_buf_copy(char *dest, int idx, int len); 
extern int printk_ratelimit_jiffies;

extern int printk_ratelimit_burst;

extern int printk_ratelimit(void);

extern int __ratelimit(int ratelimit_jiffies, int ratelimit_burst);

extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);

extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,

				   unsigned int interval_msec);

kernel/printk.c

+1 −25
Original line number Diff line number Diff line
@@ -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);

lib/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ 
	 rbtree.o radix-tree.o dump_stack.o \

	 idr.o int_sqrt.o extable.o prio_tree.o \

	 sha1.o irq_regs.o reciprocal_div.o argv_split.o \

	 proportions.o prio_heap.o

	 proportions.o prio_heap.o ratelimit.o



lib-$(CONFIG_MMU) += ioremap.o

lib-$(CONFIG_SMP) += cpumask.o

lib/ratelimit.c

0 → 100644
+51 −0
Original line number Diff line number Diff line 
/*

 * ratelimit.c - Do something with rate limit.

 *

 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>

 *

 * This file is released under the GPLv2.

 *

 */



#include <linux/kernel.h>

#include <linux/jiffies.h>

#include <linux/module.h>



/*

 * __ratelimit - rate limiting

 * @ratelimit_jiffies: minimum time in jiffies between two callbacks

 * @ratelimit_burst: number of callbacks we do before ratelimiting

 *

 * This enforces a rate limit: not more than @ratelimit_burst callbacks

 * in every ratelimit_jiffies

 */

int __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 "%s: %d messages suppressed\n",

				__func__, lost);

		return 1;

	}

	missed++;

	spin_unlock_irqrestore(&ratelimit_lock, flags);

	return 0;

}

EXPORT_SYMBOL(__ratelimit);

CRA Git | Maintained and supported by SUSTech CRA and CCSE