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	Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			57 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			57 lines
		
	
	
	
		
			1.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * ratelimit.c - Do something with rate limit.
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 *
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 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
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 *
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 * 2008-05-01 rewrite the function and use a ratelimit_state data struct as
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 * parameter. Now every user can use their own standalone ratelimit_state.
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 *
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 * This file is released under the GPLv2.
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 *
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 */
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#include <linux/kernel.h>
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#include <linux/jiffies.h>
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#include <linux/module.h>
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static DEFINE_SPINLOCK(ratelimit_lock);
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/*
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 * __ratelimit - rate limiting
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 * @rs: ratelimit_state data
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 *
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 * This enforces a rate limit: not more than @rs->ratelimit_burst callbacks
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 * in every @rs->ratelimit_jiffies
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 */
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int __ratelimit(struct ratelimit_state *rs)
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{
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	unsigned long flags;
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	if (!rs->interval)
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		return 1;
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	spin_lock_irqsave(&ratelimit_lock, flags);
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	if (!rs->begin)
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		rs->begin = jiffies;
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	if (time_is_before_jiffies(rs->begin + rs->interval)) {
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		if (rs->missed)
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			printk(KERN_WARNING "%s: %d callbacks suppressed\n",
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				__func__, rs->missed);
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		rs->begin = 0;
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		rs->printed = 0;
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		rs->missed = 0;
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	}
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	if (rs->burst && rs->burst > rs->printed)
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		goto print;
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	rs->missed++;
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	spin_unlock_irqrestore(&ratelimit_lock, flags);
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	return 0;
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print:
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	rs->printed++;
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	spin_unlock_irqrestore(&ratelimit_lock, flags);
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	return 1;
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}
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EXPORT_SYMBOL(__ratelimit);
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