From c8dfd00d5e628272a037a1dc7a9e12f0afcb3130 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@dragonflybsd.org>
Date: Mon, 30 Jul 2007 21:40:31 +0000
Subject: [PATCH] Introduce krateprintf(), a rate-controlled kprintf(), and the
 related struct krate structure.  This takes all the effort out of outputting
 rate-limited warnings to the console.

---
 sys/kern/subr_prf.c | 24 +++++++++++++++++++++++-
 sys/sys/systm.h     |  4 +++-
 sys/sys/time.h      | 15 ++++++++++++++-
 3 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c
index 80304407dc..38994fd758 100644
--- a/sys/kern/subr_prf.c
+++ b/sys/kern/subr_prf.c
@@ -37,7 +37,7 @@
  *
  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
  * $FreeBSD: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $
- * $DragonFly: src/sys/kern/subr_prf.c,v 1.17 2006/12/26 11:01:07 swildner Exp $
+ * $DragonFly: src/sys/kern/subr_prf.c,v 1.18 2007/07/30 21:40:30 dillon Exp $
  */
 
 #include "opt_ddb.h"
@@ -331,6 +331,28 @@ kvprintf(const char *fmt, __va_list ap)
 	return (retval);
 }
 
+/*
+ * Limited rate kprintf.  The passed rate structure must be initialized
+ * with the desired reporting frequency.  A frequency of 0 will result in
+ * no output.
+ */
+void
+krateprintf(struct krate *rate, const char *fmt, ...)
+{
+	__va_list ap;
+
+	if (rate->ticks != ticks) {
+		rate->ticks = ticks;
+		rate->count = 0;
+	}
+	if (rate->count < rate->freq) {
+		++rate->count;
+		__va_start(ap, fmt);
+		kvprintf(fmt, ap);
+		__va_end(ap);
+	}
+}
+
 /*
  * Print a character on console or users terminal.  If destination is
  * the console then the last bunch of characters are saved in msgbuf for
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 688cc111ff..f9f3ebae5e 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -37,7 +37,7 @@
  *
  *	@(#)systm.h	8.7 (Berkeley) 3/29/95
  * $FreeBSD: src/sys/sys/systm.h,v 1.111.2.18 2002/12/17 18:04:02 sam Exp $
- * $DragonFly: src/sys/sys/systm.h,v 1.73 2007/07/02 16:52:01 dillon Exp $
+ * $DragonFly: src/sys/sys/systm.h,v 1.74 2007/07/30 21:40:31 dillon Exp $
  */
 
 #ifndef _SYS_SYSTM_H_
@@ -132,6 +132,7 @@ struct trapframe;
 struct user;
 struct vmspace;
 struct savetls;
+struct krate;
 
 void	Debugger (const char *msg);
 void	backtrace(void);
@@ -172,6 +173,7 @@ int	log (int, const char *, ...) __printflike(2, 3);
 void	logwakeup (void);
 void	log_console (struct uio *);
 int	kprintf (const char *, ...) __printflike(1, 2);
+void	krateprintf (struct krate *, const char *, ...) __printflike(2, 3);
 int	ksnprintf (char *, size_t, const char *, ...) __printflike(3, 4);
 int	ksprintf (char *buf, const char *, ...) __printflike(2, 3);
 int	uprintf (const char *, ...) __printflike(1, 2);
diff --git a/sys/sys/time.h b/sys/sys/time.h
index 330412e68b..4f75c22ad9 100644
--- a/sys/sys/time.h
+++ b/sys/sys/time.h
@@ -32,7 +32,7 @@
  *
  *	@(#)time.h	8.5 (Berkeley) 5/4/95
  * $FreeBSD: src/sys/sys/time.h,v 1.42 1999/12/29 04:24:48 peter Exp $
- * $DragonFly: src/sys/sys/time.h,v 1.16 2007/01/07 00:42:55 dillon Exp $
+ * $DragonFly: src/sys/sys/time.h,v 1.17 2007/07/30 21:40:31 dillon Exp $
  */
 
 #ifndef _SYS_TIME_H_
@@ -191,6 +191,19 @@ struct clockinfo {
 #define TIMER_ABSTIME	0x1	/* absolute timer */
 #endif
 
+#ifdef _KERNEL
+
+/*
+ * For krateprintf()
+ */
+struct krate {
+	int freq;
+	int ticks;
+	int count;
+};
+
+#endif
+
 #ifdef _KERNEL
 extern time_t	time_second;
 extern int64_t	ntp_tick_permanent;
-- 
2.41.0