[IPV4]: Kill slow timers from IPVS, they are superfluous and inefficient these days.

include/net/ip_vs.h

@@ -407,17 +407,6 @@ union ip_vs_tphdr {
 };
 
 
-/*
- *	Slow timer for IPVS connections
- */
-struct sltimer_list {
-	struct list_head	list;
-	unsigned long		expires;
-	unsigned long		data;
-	void (*function)(unsigned long);
-};
-
-
 /*
  *	Delta sequence info structure
  *	Each ip_vs_conn has 2 (output AND input seq. changes).
@@ -535,7 +524,7 @@ struct ip_vs_conn {
 
 	/* counter and timer */
 	atomic_t		refcnt;		/* reference count */
-	struct sltimer_list	timer;		/* Expiration timer */
+	struct timer_list	timer;		/* Expiration timer */
 	volatile unsigned long	timeout;	/* timeout */
 
 	/* Flags and state transition */
@@ -939,27 +928,6 @@ extern int ip_vs_new_estimator(struct ip_vs_stats *stats);
 extern void ip_vs_kill_estimator(struct ip_vs_stats *stats);
 extern void ip_vs_zero_estimator(struct ip_vs_stats *stats);
 
-
-/*
- *      Slow timer functions for IPVS
- *      (from ip_vs_timer.c)
- */
-extern void add_sltimer(struct sltimer_list *timer);
-extern int  del_sltimer(struct sltimer_list *timer);
-extern void mod_sltimer(struct sltimer_list *timer, unsigned long expires);
-extern void ip_vs_sltimer_init(void);
-extern void ip_vs_sltimer_cleanup(void);
-static inline void init_sltimer(struct sltimer_list *timer)
-{
-	timer->list.next = timer->list.prev = NULL;
-}
-
-static inline int sltimer_pending(const struct sltimer_list *timer)
-{
-	return timer->list.next != NULL;
-}
-
-
 /*
  *	Various IPVS packet transmitters (from ip_vs_xmit.c)
  */

net/ipv4/ipvs/Makefile

@@ -16,7 +16,7 @@ ip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_ESP) += ip_vs_proto_esp.o
 ip_vs_proto-objs-$(CONFIG_IP_VS_PROTO_AH) += ip_vs_proto_ah.o
 
 ip_vs-objs :=	ip_vs_conn.o ip_vs_core.o ip_vs_ctl.o ip_vs_sched.o	   \
-		ip_vs_xmit.o ip_vs_timer.o ip_vs_app.o ip_vs_sync.o	   \
+		ip_vs_xmit.o ip_vs_app.o ip_vs_sync.o	   		   \
 		ip_vs_est.o ip_vs_proto.o ip_vs_proto_icmp.o		   \
 		$(ip_vs_proto-objs-y)
 

net/ipv4/ipvs/ip_vs_conn.c

@@ -282,7 +282,7 @@ struct ip_vs_conn *ip_vs_conn_out_get
 void ip_vs_conn_put(struct ip_vs_conn *cp)
 {
 	/* reset it expire in its timeout */
-	mod_sltimer(&cp->timer, jiffies+cp->timeout);
+	mod_timer(&cp->timer, jiffies+cp->timeout);
 
 	__ip_vs_conn_put(cp);
 }
@@ -508,8 +508,7 @@ static void ip_vs_conn_expire(unsigned long data)
 	 */
 	if (likely(atomic_read(&cp->refcnt) == 1)) {
 		/* make sure that there is no timer on it now */
-		if (sltimer_pending(&cp->timer))
-			del_sltimer(&cp->timer);
+		del_timer_sync(&cp->timer);
 
 		/* does anybody control me? */
 		if (cp->control)
@@ -542,7 +541,7 @@ static void ip_vs_conn_expire(unsigned long data)
 void ip_vs_conn_expire_now(struct ip_vs_conn *cp)
 {
 	cp->timeout = 0;
-	mod_sltimer(&cp->timer, jiffies);
+	mod_timer(&cp->timer, jiffies);
 	__ip_vs_conn_put(cp);
 }
 
@@ -566,7 +565,7 @@ ip_vs_conn_new(int proto, __u32 caddr, __u16 cport, __u32 vaddr, __u16 vport,
 
 	memset(cp, 0, sizeof(*cp));
 	INIT_LIST_HEAD(&cp->c_list);
-	init_sltimer(&cp->timer);
+	init_timer(&cp->timer);
 	cp->timer.data     = (unsigned long)cp;
 	cp->timer.function = ip_vs_conn_expire;
 	cp->protocol	   = proto;

net/ipv4/ipvs/ip_vs_core.c

@@ -1092,7 +1092,6 @@ static int __init ip_vs_init(void)
 		goto cleanup_nothing;
 	}
 
-	ip_vs_sltimer_init();
 	ip_vs_protocol_init();
 
 	ret = ip_vs_app_init();
@@ -1144,7 +1143,6 @@ static int __init ip_vs_init(void)
 	ip_vs_app_cleanup();
   cleanup_protocol:
 	ip_vs_protocol_cleanup();
-	ip_vs_sltimer_cleanup();
 	ip_vs_control_cleanup();
   cleanup_nothing:
 	return ret;
@@ -1159,7 +1157,6 @@ static void __exit ip_vs_cleanup(void)
 	ip_vs_conn_cleanup();
 	ip_vs_app_cleanup();
 	ip_vs_protocol_cleanup();
-	ip_vs_sltimer_cleanup();
 	ip_vs_control_cleanup();
 	IP_VS_INFO("ipvs unloaded.\n");
 }

net/ipv4/ipvs/ip_vs_timer.c

-/*
- * IPVS         An implementation of the IP virtual server support for the
- *              LINUX operating system.  IPVS is now implemented as a module
- *              over the Netfilter framework. IPVS can be used to build a
- *              high-performance and highly available server based on a
- *              cluster of servers.
- *
- * Version:     $Id: ip_vs_timer.c,v 1.11 2003/06/08 09:31:19 wensong Exp $
- *
- * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
- *              Julian Anastasov <ja@ssi.bg>
- *
- *              This program is free software; you can redistribute it and/or
- *              modify it under the terms of the GNU General Public License
- *              as published by the Free Software Foundation; either version
- *              2 of the License, or (at your option) any later version.
- *
- * Changes:
- *
- */
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/timer.h>
-
-#include <net/ip_vs.h>
-
-/*
- * The following block implements slow timers for IPVS, most code is stolen
- * from linux/kernel/timer.c.
- * Slow timer is used to avoid the overhead of cascading timers, when lots
- * of connection entries (>50,000) are cluttered in the system.
- */
-#define SHIFT_BITS 6
-#define TVN_BITS 8
-#define TVR_BITS 10
-#define TVN_SIZE (1 << TVN_BITS)
-#define TVR_SIZE (1 << TVR_BITS)
-#define TVN_MASK (TVN_SIZE - 1)
-#define TVR_MASK (TVR_SIZE - 1)
-
-struct sltimer_vec {
-	int index;
-	struct list_head vec[TVN_SIZE];
-};
-
-struct sltimer_vec_root {
-	int index;
-	struct list_head vec[TVR_SIZE];
-};
-
-static struct sltimer_vec sltv3 = { 0 };
-static struct sltimer_vec sltv2 = { 0 };
-static struct sltimer_vec_root sltv1 = { 0 };
-
-static struct sltimer_vec * const sltvecs[] = {
-	(struct sltimer_vec *)&sltv1, &sltv2, &sltv3
-};
-
-#define NOOF_SLTVECS (sizeof(sltvecs) / sizeof(sltvecs[0]))
-
-static void init_sltimervecs(void)
-{
-	int i;
-
-	for (i = 0; i < TVN_SIZE; i++) {
-		INIT_LIST_HEAD(sltv3.vec + i);
-		INIT_LIST_HEAD(sltv2.vec + i);
-	}
-	for (i = 0; i < TVR_SIZE; i++)
-		INIT_LIST_HEAD(sltv1.vec + i);
-}
-
-static unsigned long sltimer_jiffies = 0;
-
-static inline void internal_add_sltimer(struct sltimer_list *timer)
-{
-	/*
-	 * must hold the sltimer lock when calling this
-	 */
-	unsigned long expires = timer->expires;
-	unsigned long idx = expires - sltimer_jiffies;
-	struct list_head * vec;
-
-	if (idx < 1 << (SHIFT_BITS + TVR_BITS)) {
-		int i = (expires >> SHIFT_BITS) & TVR_MASK;
-		vec = sltv1.vec + i;
-	} else if (idx < 1 << (SHIFT_BITS + TVR_BITS + TVN_BITS)) {
-		int i = (expires >> (SHIFT_BITS+TVR_BITS)) & TVN_MASK;
-		vec = sltv2.vec + i;
-	} else if ((signed long) idx < 0) {
-		/*
-		 * can happen if you add a timer with expires == jiffies,
-		 * or you set a timer to go off in the past
-		 */
-		vec = sltv1.vec + sltv1.index;
-	} else if (idx <= 0xffffffffUL) {
-		int i = (expires >> (SHIFT_BITS+TVR_BITS+TVN_BITS)) & TVN_MASK;
-		vec = sltv3.vec + i;
-	} else {
-		/* Can only get here on architectures with 64-bit jiffies */
-		INIT_LIST_HEAD(&timer->list);
-	}
-	/*
-	 * Timers are FIFO!
-	 */
-	list_add(&timer->list, vec->prev);
-}
-
-
-static spinlock_t __ip_vs_sltimerlist_lock = SPIN_LOCK_UNLOCKED;
-
-void add_sltimer(struct sltimer_list *timer)
-{
-	spin_lock(&__ip_vs_sltimerlist_lock);
-	if (timer->list.next)
-		goto bug;
-	internal_add_sltimer(timer);
-  out:
-	spin_unlock(&__ip_vs_sltimerlist_lock);
-	return;
-
-  bug:
-	printk("bug: kernel sltimer added twice at %p.\n",
-	       __builtin_return_address(0));
-	goto out;
-}
-
-static inline int detach_sltimer(struct sltimer_list *timer)
-{
-	if (!sltimer_pending(timer))
-		return 0;
-	list_del(&timer->list);
-	return 1;
-}
-
-void mod_sltimer(struct sltimer_list *timer, unsigned long expires)
-{
-	int ret;
-
-	spin_lock(&__ip_vs_sltimerlist_lock);
-	timer->expires = expires;
-	ret = detach_sltimer(timer);
-	internal_add_sltimer(timer);
-	spin_unlock(&__ip_vs_sltimerlist_lock);
-}
-
-int del_sltimer(struct sltimer_list * timer)
-{
-	int ret;
-
-	spin_lock(&__ip_vs_sltimerlist_lock);
-	ret = detach_sltimer(timer);
-	timer->list.next = timer->list.prev = 0;
-	spin_unlock(&__ip_vs_sltimerlist_lock);
-	return ret;
-}
-
-
-static inline void cascade_sltimers(struct sltimer_vec *tv)
-{
-	/*
-	 * cascade all the timers from tv up one level
-	 */
-	struct list_head *head, *curr, *next;
-
-	head = tv->vec + tv->index;
-	curr = head->next;
-
-	/*
-	 * We are removing _all_ timers from the list, so we don't  have to
-	 * detach them individually, just clear the list afterwards.
-	 */
-	while (curr != head) {
-		struct sltimer_list *tmp;
-
-		tmp = list_entry(curr, struct sltimer_list, list);
-		next = curr->next;
-		list_del(curr); // not needed
-		internal_add_sltimer(tmp);
-		curr = next;
-	}
-	INIT_LIST_HEAD(head);
-	tv->index = (tv->index + 1) & TVN_MASK;
-}
-
-static inline void run_sltimer_list(void)
-{
-	spin_lock(&__ip_vs_sltimerlist_lock);
-	while ((long)(jiffies - sltimer_jiffies) >= 0) {
-		struct list_head *head, *curr;
-		if (!sltv1.index) {
-			int n = 1;
-			do {
-				cascade_sltimers(sltvecs[n]);
-			} while (sltvecs[n]->index == 1 && ++n < NOOF_SLTVECS);
-		}
-	  repeat:
-		head = sltv1.vec + sltv1.index;
-		curr = head->next;
-		if (curr != head) {
-			struct sltimer_list *timer;
-			void (*fn)(unsigned long);
-			unsigned long data;
-
-			timer = list_entry(curr, struct sltimer_list, list);
-			fn = timer->function;
-			data= timer->data;
-
-			detach_sltimer(timer);
-			timer->list.next = timer->list.prev = NULL;
-			spin_unlock(&__ip_vs_sltimerlist_lock);
-			fn(data);
-			spin_lock(&__ip_vs_sltimerlist_lock);
-			goto repeat;
-		}
-		sltimer_jiffies += 1<<SHIFT_BITS;
-		sltv1.index = (sltv1.index + 1) & TVR_MASK;
-	}
-	spin_unlock(&__ip_vs_sltimerlist_lock);
-}
-
-static struct timer_list slow_timer;
-
-/*
- *  Slow timer handler is activated every second
- */
-#define SLTIMER_PERIOD	     1*HZ
-
-static void sltimer_handler(unsigned long data)
-{
-	run_sltimer_list();
-
-	update_defense_level();
-	if (atomic_read(&ip_vs_dropentry))
-		ip_vs_random_dropentry();
-
-	mod_timer(&slow_timer, (jiffies + SLTIMER_PERIOD));
-}
-
-
-void ip_vs_sltimer_init(void)
-{
-	/* initialize the slow timer vectors */
-	init_sltimervecs();
-
-	/* initialize the slow timer jiffies and the vector indexes */
-	sltimer_jiffies = jiffies;
-	sltv1.index = (sltimer_jiffies >> SHIFT_BITS) & TVR_MASK;
-	sltv2.index = (sltimer_jiffies >> (SHIFT_BITS + TVR_BITS)) & TVN_MASK;
-	sltv3.index = (sltimer_jiffies >> (SHIFT_BITS + TVR_BITS + TVN_BITS))
-		& TVN_MASK;
-
-	/* Hook the slow_timer handler in the system timer */
-	init_timer(&slow_timer);
-	slow_timer.function = sltimer_handler;
-	slow_timer.expires = jiffies+SLTIMER_PERIOD;
-	add_timer(&slow_timer);
-}
-
-
-void ip_vs_sltimer_cleanup(void)
-{
-	del_timer_sync(&slow_timer);
-}