502  * To prevent flipping in and out of rate-limiting, there is a hysteresis
529     u_int max_accum, u_int hysteresis, u_int log_every)  in log_ratelimit_init()  argument
534 	rl->hysteresis = hysteresis;  in log_ratelimit_init()
537 	    rl, rl->threshold, rl->max_accum, rl->hysteresis, rl->log_every));  in log_ratelimit_init()
554 	    rl->max_accum, rl->hysteresis,  in log_ratelimit()
593 		    rl->hysteresis, rl->hysteresis_start == 0 ? -1 :  in log_ratelimit()
597 			/* active, but under threshold; hysteresis */  in log_ratelimit()
598 			if (olast_event + rl->hysteresis < now) {  in log_ratelimit()
599 				/* hysteresis expired before this event */  in log_ratelimit()
600 				RLDBG(("hysteresis preexpired"));  in log_ratelimit()
603 			RLDBG(("start hysteresis"));  in log_ratelimit()
605 		} else if (rl->hysteresis_start + rl->hysteresis < now) {  in log_ratelimit()
606 			/* Hysteresis period expired, transition to inactive */  in log_ratelimit()
607 			RLDBG(("complete hysteresis"));  in log_ratelimit()
620 		/* ratelimiting active, but in hysteresis period */  in log_ratelimit()
633 		/* active and over threshold; reset hysteresis timer */  in log_ratelimit()
634 		RLDBG(("clear hysteresis"));  in log_ratelimit()
638 	/* over threshold or in hysteresis period; log periodically */  in log_ratelimit()