From 47083fc0735f5145b72fc31236d07339dc52b908 Mon Sep 17 00:00:00 2001
From: Jesper Dangaard Brouer <hawk@comx.dk>
Date: Mon, 16 Jun 2008 16:39:32 -0700
Subject: [PATCH] pkt_sched: Change HTB_HYSTERESIS to a runtime parameter
htb_hysteresis.
Add a htb_hysteresis parameter to htb_sch.ko and by sysfs magic make
it runtime adjustable via
/sys/module/sch_htb/parameters/htb_hysteresis mode 640.
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Acked-by: Martin Devera <devik@cdi.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/sched/sch_htb.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 9134f029ee0f2..6807c97985a54 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -28,6 +28,7 @@
* $Id: sch_htb.c,v 1.25 2003/12/07 11:08:25 devik Exp devik $
*/
#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
@@ -53,13 +54,17 @@
*/
#define HTB_HSIZE 16 /* classid hash size */
-#define HTB_HYSTERESIS 0 /* whether to use mode hysteresis for speedup */
+static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */
#define HTB_VER 0x30011 /* major must be matched with number suplied by TC as version */
#if HTB_VER >> 16 != TC_HTB_PROTOVER
#error "Mismatched sch_htb.c and pkt_sch.h"
#endif
+/* Module parameter and sysfs export */
+module_param (htb_hysteresis, int, 0640);
+MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate");
+
/* used internaly to keep status of single class */
enum htb_cmode {
HTB_CANT_SEND, /* class can't send and can't borrow */
@@ -462,19 +467,21 @@ static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
htb_remove_class_from_row(q, cl, mask);
}
-#if HTB_HYSTERESIS
static inline long htb_lowater(const struct htb_class *cl)
{
- return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
+ if (htb_hysteresis)
+ return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
+ else
+ return 0;
}
static inline long htb_hiwater(const struct htb_class *cl)
{
- return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
+ if (htb_hysteresis)
+ return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
+ else
+ return 0;
}
-#else
-#define htb_lowater(cl) (0)
-#define htb_hiwater(cl) (0)
-#endif
+
/**
* htb_class_mode - computes and returns current class mode
--
2.30.2