[net-next-2.6.git] / net / core / drop_monitor.c

/*
 * Monitoring code for network dropped packet alerts
 *
 * Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
 */

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/string.h>
#include <linux/if_arp.h>
#include <linux/inetdevice.h>
#include <linux/inet.h>
#include <linux/interrupt.h>
#include <linux/netpoll.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <linux/netlink.h>
#include <linux/net_dropmon.h>
#include <linux/percpu.h>
#include <linux/timer.h>
#include <linux/bitops.h>
#include <net/genetlink.h>
#include <net/netevent.h>

#include <trace/skb.h>
#include <trace/napi.h>

#include <asm/unaligned.h>

#define TRACE_ON 1
#define TRACE_OFF 0

static void send_dm_alert(struct work_struct *unused);


/*
 * Globals, our netlink socket pointer
 * and the work handle that will send up
 * netlink alerts
 */
static int trace_state = TRACE_OFF;
static spinlock_t trace_state_lock = SPIN_LOCK_UNLOCKED;

struct per_cpu_dm_data {
	struct work_struct dm_alert_work;
	struct sk_buff *skb;
	atomic_t dm_hit_count;
	struct timer_list send_timer;
};

struct dm_hw_stat_delta {
	struct net_device *dev;
	struct list_head list;
	struct rcu_head rcu;
	unsigned long last_drop_val;
};

static struct genl_family net_drop_monitor_family = {
	.id             = GENL_ID_GENERATE,
	.hdrsize        = 0,
	.name           = "NET_DM",
	.version        = 2,
	.maxattr        = NET_DM_CMD_MAX,
};

static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);

static int dm_hit_limit = 64;
static int dm_delay = 1;
static unsigned long dm_hw_check_delta = 2*HZ;
static LIST_HEAD(hw_stats_list);

static void reset_per_cpu_data(struct per_cpu_dm_data *data)
{
	size_t al;
	struct net_dm_alert_msg *msg;
	struct nlattr *nla;

	al = sizeof(struct net_dm_alert_msg);
	al += dm_hit_limit * sizeof(struct net_dm_drop_point);
	al += sizeof(struct nlattr);

	data->skb = genlmsg_new(al, GFP_KERNEL);
	genlmsg_put(data->skb, 0, 0, &net_drop_monitor_family,
			0, NET_DM_CMD_ALERT);
	nla = nla_reserve(data->skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));
	msg = nla_data(nla);
	memset(msg, 0, al);
	atomic_set(&data->dm_hit_count, dm_hit_limit);
}

static void send_dm_alert(struct work_struct *unused)
{
	struct sk_buff *skb;
	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);

	/*
	 * Grab the skb we're about to send
	 */
	skb = data->skb;

	/*
	 * Replace it with a new one
	 */
	reset_per_cpu_data(data);

	/*
	 * Ship it!
	 */
	genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL);

}

/*
 * This is the timer function to delay the sending of an alert
 * in the event that more drops will arrive during the
 * hysteresis period.  Note that it operates under the timer interrupt
 * so we don't need to disable preemption here
 */
static void sched_send_work(unsigned long unused)
{
	struct per_cpu_dm_data *data =  &__get_cpu_var(dm_cpu_data);

	schedule_work(&data->dm_alert_work);
}

static void trace_drop_common(struct sk_buff *skb, void *location)
{
	struct net_dm_alert_msg *msg;
	struct nlmsghdr *nlh;
	struct nlattr *nla;
	int i;
	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);


	if (!atomic_add_unless(&data->dm_hit_count, -1, 0)) {
		/*
		 * we're already at zero, discard this hit
		 */
		goto out;
	}

	nlh = (struct nlmsghdr *)data->skb->data;
	nla = genlmsg_data(nlmsg_data(nlh));
	msg = nla_data(nla);
	for (i = 0; i < msg->entries; i++) {
		if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
			msg->points[i].count++;
			goto out;
		}
	}

	/*
	 * We need to create a new entry
	 */
	__nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
	nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
	memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
	msg->points[msg->entries].count = 1;
	msg->entries++;

	if (!timer_pending(&data->send_timer)) {
		data->send_timer.expires = jiffies + dm_delay * HZ;
		add_timer_on(&data->send_timer, smp_processor_id());
	}

out:
	return;
}

static void trace_kfree_skb_hit(struct sk_buff *skb, void *location)
{
	trace_drop_common(skb, location);
}

static void trace_napi_poll_hit(struct napi_struct *napi)
{
	struct dm_hw_stat_delta *new_stat;

	/*
	 * Ratelimit our check time to dm_hw_check_delta jiffies
	 */
	if (!time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
		return;

	rcu_read_lock();
	list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
		if ((new_stat->dev == napi->dev)  &&
		    (napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
			trace_drop_common(NULL, NULL);
			new_stat->last_drop_val = napi->dev->stats.rx_dropped;
			break;
		}
	}
	rcu_read_unlock();
}


static void free_dm_hw_stat(struct rcu_head *head)
{
	struct dm_hw_stat_delta *n;
	n = container_of(head, struct dm_hw_stat_delta, rcu);
	kfree(n);
}

static int set_all_monitor_traces(int state)
{
	int rc = 0;
	struct dm_hw_stat_delta *new_stat = NULL;
	struct dm_hw_stat_delta *temp;

	spin_lock(&trace_state_lock);

	switch (state) {
	case TRACE_ON:
		rc |= register_trace_kfree_skb(trace_kfree_skb_hit);
		rc |= register_trace_napi_poll(trace_napi_poll_hit);
		break;
	case TRACE_OFF:
		rc |= unregister_trace_kfree_skb(trace_kfree_skb_hit);
		rc |= unregister_trace_napi_poll(trace_napi_poll_hit);

		tracepoint_synchronize_unregister();

		/*
		 * Clean the device list
		 */
		list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
			if (new_stat->dev == NULL) {
				list_del_rcu(&new_stat->list);
				call_rcu(&new_stat->rcu, free_dm_hw_stat);
			}
		}
		break;
	default:
		rc = 1;
		break;
	}

	if (!rc)
		trace_state = state;

	spin_unlock(&trace_state_lock);

	if (rc)
		return -EINPROGRESS;
	return rc;
}


static int net_dm_cmd_config(struct sk_buff *skb,
			struct genl_info *info)
{
	return -ENOTSUPP;
}

static int net_dm_cmd_trace(struct sk_buff *skb,
			struct genl_info *info)
{
	switch (info->genlhdr->cmd) {
	case NET_DM_CMD_START:
		return set_all_monitor_traces(TRACE_ON);
		break;
	case NET_DM_CMD_STOP:
		return set_all_monitor_traces(TRACE_OFF);
		break;
	}

	return -ENOTSUPP;
}

static int dropmon_net_event(struct notifier_block *ev_block,
			unsigned long event, void *ptr)
{
	struct net_device *dev = ptr;
	struct dm_hw_stat_delta *new_stat = NULL;
	struct dm_hw_stat_delta *tmp;

	switch (event) {
	case NETDEV_REGISTER:
		new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);

		if (!new_stat)
			goto out;

		new_stat->dev = dev;
		INIT_RCU_HEAD(&new_stat->rcu);
		spin_lock(&trace_state_lock);
		list_add_rcu(&new_stat->list, &hw_stats_list);
		spin_unlock(&trace_state_lock);
		break;
	case NETDEV_UNREGISTER:
		spin_lock(&trace_state_lock);
		list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
			if (new_stat->dev == dev) {
				new_stat->dev = NULL;
				if (trace_state == TRACE_OFF) {
					list_del_rcu(&new_stat->list);
					call_rcu(&new_stat->rcu, free_dm_hw_stat);
					break;
				}
			}
		}
		spin_unlock(&trace_state_lock);
		break;
	}
out:
	return NOTIFY_DONE;
}

static struct genl_ops dropmon_ops[] = {
	{
		.cmd = NET_DM_CMD_CONFIG,
		.doit = net_dm_cmd_config,
	},
	{
		.cmd = NET_DM_CMD_START,
		.doit = net_dm_cmd_trace,
	},
	{
		.cmd = NET_DM_CMD_STOP,
		.doit = net_dm_cmd_trace,
	},
};

static struct notifier_block dropmon_net_notifier = {
	.notifier_call = dropmon_net_event
};

static int __init init_net_drop_monitor(void)
{
	int cpu;
	int rc, i, ret;
	struct per_cpu_dm_data *data;
	printk(KERN_INFO "Initalizing network drop monitor service\n");

	if (sizeof(void *) > 8) {
		printk(KERN_ERR "Unable to store program counters on this arch, Drop monitor failed\n");
		return -ENOSPC;
	}

	if (genl_register_family(&net_drop_monitor_family) < 0) {
		printk(KERN_ERR "Could not create drop monitor netlink family\n");
		return -EFAULT;
	}

	rc = -EFAULT;

	for (i = 0; i < ARRAY_SIZE(dropmon_ops); i++) {
		ret = genl_register_ops(&net_drop_monitor_family,
					&dropmon_ops[i]);
		if (ret) {
			printk(KERN_CRIT "Failed to register operation %d\n",
				dropmon_ops[i].cmd);
			goto out_unreg;
		}
	}

	rc = register_netdevice_notifier(&dropmon_net_notifier);
	if (rc < 0) {
		printk(KERN_CRIT "Failed to register netdevice notifier\n");
		goto out_unreg;
	}

	rc = 0;

	for_each_present_cpu(cpu) {
		data = &per_cpu(dm_cpu_data, cpu);
		reset_per_cpu_data(data);
		INIT_WORK(&data->dm_alert_work, send_dm_alert);
		init_timer(&data->send_timer);
		data->send_timer.data = cpu;
		data->send_timer.function = sched_send_work;
	}

	goto out;

out_unreg:
	genl_unregister_family(&net_drop_monitor_family);
out:
	return rc;
}

late_initcall(init_net_drop_monitor);
Commit	Line	Data
9a8afc8d NH	1	/*
	2	* Monitoring code for network dropped packet alerts
	3	*
	4	* Copyright (C) 2009 Neil Horman <nhorman@tuxdriver.com>
	5	*/
	6
	7	#include <linux/netdevice.h>
	8	#include <linux/etherdevice.h>
	9	#include <linux/string.h>
	10	#include <linux/if_arp.h>
	11	#include <linux/inetdevice.h>
	12	#include <linux/inet.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/netpoll.h>
	15	#include <linux/sched.h>
	16	#include <linux/delay.h>
	17	#include <linux/types.h>
	18	#include <linux/workqueue.h>
	19	#include <linux/netlink.h>
	20	#include <linux/net_dropmon.h>
	21	#include <linux/percpu.h>
	22	#include <linux/timer.h>
	23	#include <linux/bitops.h>
	24	#include <net/genetlink.h>
4ea7e386	25	#include <net/netevent.h>
9a8afc8d NH	26
9a8afc8d NH	27	#include <trace/skb.h>
4ea7e386	28	#include <trace/napi.h>
9a8afc8d NH	29
	30	#include <asm/unaligned.h>
	31
	32	#define TRACE_ON 1
	33	#define TRACE_OFF 0
	34
	35	static void send_dm_alert(struct work_struct *unused);
	36
	37
	38	/*
	39	* Globals, our netlink socket pointer
	40	* and the work handle that will send up
	41	* netlink alerts
	42	*/
4ea7e386 NH	43	static int trace_state = TRACE_OFF;
4ea7e386 NH	44	static spinlock_t trace_state_lock = SPIN_LOCK_UNLOCKED;
9a8afc8d NH	45
	46	struct per_cpu_dm_data {
	47	struct work_struct dm_alert_work;
	48	struct sk_buff *skb;
	49	atomic_t dm_hit_count;
	50	struct timer_list send_timer;
	51	};
	52
4ea7e386 NH	53	struct dm_hw_stat_delta {
	54	struct net_device *dev;
	55	struct list_head list;
	56	struct rcu_head rcu;
	57	unsigned long last_drop_val;
	58	};
	59
9a8afc8d NH	60	static struct genl_family net_drop_monitor_family = {
	61	.id = GENL_ID_GENERATE,
	62	.hdrsize = 0,
	63	.name = "NET_DM",
683703a2	64	.version = 2,
9a8afc8d NH	65	.maxattr = NET_DM_CMD_MAX,
	66	};
	67
	68	static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
	69
	70	static int dm_hit_limit = 64;
	71	static int dm_delay = 1;
4ea7e386 NH	72	static unsigned long dm_hw_check_delta = 2*HZ;
4ea7e386 NH	73	static LIST_HEAD(hw_stats_list);
9a8afc8d NH	74
	75	static void reset_per_cpu_data(struct per_cpu_dm_data *data)
	76	{
	77	size_t al;
	78	struct net_dm_alert_msg *msg;
683703a2	79	struct nlattr *nla;
9a8afc8d NH	80
	81	al = sizeof(struct net_dm_alert_msg);
	82	al += dm_hit_limit * sizeof(struct net_dm_drop_point);
683703a2 NH	83	al += sizeof(struct nlattr);
683703a2 NH	84
9a8afc8d NH	85	data->skb = genlmsg_new(al, GFP_KERNEL);
	86	genlmsg_put(data->skb, 0, 0, &net_drop_monitor_family,
	87	0, NET_DM_CMD_ALERT);
683703a2 NH	88	nla = nla_reserve(data->skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg));
683703a2 NH	89	msg = nla_data(nla);
9a8afc8d NH	90	memset(msg, 0, al);
	91	atomic_set(&data->dm_hit_count, dm_hit_limit);
	92	}
	93
	94	static void send_dm_alert(struct work_struct *unused)
	95	{
	96	struct sk_buff *skb;
	97	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	98
	99	/*
	100	* Grab the skb we're about to send
	101	*/
	102	skb = data->skb;
	103
	104	/*
	105	* Replace it with a new one
	106	*/
	107	reset_per_cpu_data(data);
	108
	109	/*
	110	* Ship it!
	111	*/
	112	genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL);
	113
	114	}
	115
	116	/*
	117	* This is the timer function to delay the sending of an alert
	118	* in the event that more drops will arrive during the
	119	* hysteresis period. Note that it operates under the timer interrupt
	120	* so we don't need to disable preemption here
	121	*/
	122	static void sched_send_work(unsigned long unused)
	123	{
	124	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	125
	126	schedule_work(&data->dm_alert_work);
	127	}
	128
4ea7e386	129	static void trace_drop_common(struct sk_buff skb, void location)
9a8afc8d NH	130	{
	131	struct net_dm_alert_msg *msg;
	132	struct nlmsghdr *nlh;
683703a2	133	struct nlattr *nla;
9a8afc8d NH	134	int i;
	135	struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
	136
	137
	138	if (!atomic_add_unless(&data->dm_hit_count, -1, 0)) {
	139	/*
	140	* we're already at zero, discard this hit
	141	*/
	142	goto out;
	143	}
	144
	145	nlh = (struct nlmsghdr *)data->skb->data;
683703a2 NH	146	nla = genlmsg_data(nlmsg_data(nlh));
683703a2 NH	147	msg = nla_data(nla);
9a8afc8d NH	148	for (i = 0; i < msg->entries; i++) {
	149	if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) {
	150	msg->points[i].count++;
	151	goto out;
	152	}
	153	}
	154
	155	/*
	156	* We need to create a new entry
	157	*/
	158	__nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
683703a2	159	nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point));
9a8afc8d NH	160	memcpy(msg->points[msg->entries].pc, &location, sizeof(void *));
	161	msg->points[msg->entries].count = 1;
	162	msg->entries++;
	163
	164	if (!timer_pending(&data->send_timer)) {
	165	data->send_timer.expires = jiffies + dm_delay * HZ;
	166	add_timer_on(&data->send_timer, smp_processor_id());
	167	}
	168
	169	out:
	170	return;
	171	}
	172
4ea7e386 NH	173	static void trace_kfree_skb_hit(struct sk_buff skb, void location)
	174	{
	175	trace_drop_common(skb, location);
	176	}
	177
	178	static void trace_napi_poll_hit(struct napi_struct *napi)
	179	{
	180	struct dm_hw_stat_delta *new_stat;
	181
	182	/*
	183	* Ratelimit our check time to dm_hw_check_delta jiffies
	184	*/
	185	if (!time_after(jiffies, napi->dev->last_rx + dm_hw_check_delta))
	186	return;
	187
	188	rcu_read_lock();
	189	list_for_each_entry_rcu(new_stat, &hw_stats_list, list) {
	190	if ((new_stat->dev == napi->dev) &&
	191	(napi->dev->stats.rx_dropped != new_stat->last_drop_val)) {
	192	trace_drop_common(NULL, NULL);
	193	new_stat->last_drop_val = napi->dev->stats.rx_dropped;
	194	break;
	195	}
	196	}
	197	rcu_read_unlock();
	198	}
	199
	200
	201	static void free_dm_hw_stat(struct rcu_head *head)
	202	{
	203	struct dm_hw_stat_delta *n;
	204	n = container_of(head, struct dm_hw_stat_delta, rcu);
	205	kfree(n);
	206	}
	207
9a8afc8d NH	208	static int set_all_monitor_traces(int state)
	209	{
	210	int rc = 0;
4ea7e386 NH	211	struct dm_hw_stat_delta *new_stat = NULL;
	212	struct dm_hw_stat_delta *temp;
	213
	214	spin_lock(&trace_state_lock);
9a8afc8d NH	215
	216	switch (state) {
	217	case TRACE_ON:
	218	rc \|= register_trace_kfree_skb(trace_kfree_skb_hit);
4ea7e386	219	rc \|= register_trace_napi_poll(trace_napi_poll_hit);
9a8afc8d NH	220	break;
	221	case TRACE_OFF:
	222	rc \|= unregister_trace_kfree_skb(trace_kfree_skb_hit);
4ea7e386	223	rc \|= unregister_trace_napi_poll(trace_napi_poll_hit);
9a8afc8d NH	224
9a8afc8d NH	225	tracepoint_synchronize_unregister();
4ea7e386 NH	226
	227	/*
	228	* Clean the device list
	229	*/
	230	list_for_each_entry_safe(new_stat, temp, &hw_stats_list, list) {
	231	if (new_stat->dev == NULL) {
	232	list_del_rcu(&new_stat->list);
	233	call_rcu(&new_stat->rcu, free_dm_hw_stat);
	234	}
	235	}
9a8afc8d NH	236	break;
	237	default:
	238	rc = 1;
	239	break;
	240	}
	241
4ea7e386 NH	242	if (!rc)
	243	trace_state = state;
	244
	245	spin_unlock(&trace_state_lock);
	246
9a8afc8d NH	247	if (rc)
	248	return -EINPROGRESS;
	249	return rc;
	250	}
	251
	252
	253	static int net_dm_cmd_config(struct sk_buff *skb,
	254	struct genl_info *info)
	255	{
	256	return -ENOTSUPP;
	257	}
	258
	259	static int net_dm_cmd_trace(struct sk_buff *skb,
	260	struct genl_info *info)
	261	{
	262	switch (info->genlhdr->cmd) {
	263	case NET_DM_CMD_START:
	264	return set_all_monitor_traces(TRACE_ON);
	265	break;
	266	case NET_DM_CMD_STOP:
	267	return set_all_monitor_traces(TRACE_OFF);
	268	break;
	269	}
	270
	271	return -ENOTSUPP;
	272	}
	273
4ea7e386 NH	274	static int dropmon_net_event(struct notifier_block *ev_block,
	275	unsigned long event, void *ptr)
	276	{
	277	struct net_device *dev = ptr;
	278	struct dm_hw_stat_delta *new_stat = NULL;
	279	struct dm_hw_stat_delta *tmp;
	280
	281	switch (event) {
	282	case NETDEV_REGISTER:
	283	new_stat = kzalloc(sizeof(struct dm_hw_stat_delta), GFP_KERNEL);
	284
	285	if (!new_stat)
	286	goto out;
	287
	288	new_stat->dev = dev;
	289	INIT_RCU_HEAD(&new_stat->rcu);
	290	spin_lock(&trace_state_lock);
	291	list_add_rcu(&new_stat->list, &hw_stats_list);
	292	spin_unlock(&trace_state_lock);
	293	break;
	294	case NETDEV_UNREGISTER:
	295	spin_lock(&trace_state_lock);
	296	list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
	297	if (new_stat->dev == dev) {
	298	new_stat->dev = NULL;
	299	if (trace_state == TRACE_OFF) {
	300	list_del_rcu(&new_stat->list);
	301	call_rcu(&new_stat->rcu, free_dm_hw_stat);
	302	break;
	303	}
	304	}
	305	}
	306	spin_unlock(&trace_state_lock);
	307	break;
	308	}
	309	out:
	310	return NOTIFY_DONE;
	311	}
9a8afc8d NH	312
	313	static struct genl_ops dropmon_ops[] = {
	314	{
	315	.cmd = NET_DM_CMD_CONFIG,
	316	.doit = net_dm_cmd_config,
	317	},
	318	{
	319	.cmd = NET_DM_CMD_START,
	320	.doit = net_dm_cmd_trace,
	321	},
	322	{
	323	.cmd = NET_DM_CMD_STOP,
	324	.doit = net_dm_cmd_trace,
	325	},
	326	};
	327
4ea7e386 NH	328	static struct notifier_block dropmon_net_notifier = {
	329	.notifier_call = dropmon_net_event
	330	};
	331
9a8afc8d NH	332	static int __init init_net_drop_monitor(void)
	333	{
	334	int cpu;
	335	int rc, i, ret;
	336	struct per_cpu_dm_data *data;
	337	printk(KERN_INFO "Initalizing network drop monitor service\n");
	338
	339	if (sizeof(void *) > 8) {
	340	printk(KERN_ERR "Unable to store program counters on this arch, Drop monitor failed\n");
	341	return -ENOSPC;
	342	}
	343
	344	if (genl_register_family(&net_drop_monitor_family) < 0) {
	345	printk(KERN_ERR "Could not create drop monitor netlink family\n");
	346	return -EFAULT;
	347	}
	348
	349	rc = -EFAULT;
	350
	351	for (i = 0; i < ARRAY_SIZE(dropmon_ops); i++) {
	352	ret = genl_register_ops(&net_drop_monitor_family,
	353	&dropmon_ops[i]);
	354	if (ret) {
4ea7e386	355	printk(KERN_CRIT "Failed to register operation %d\n",
9a8afc8d NH	356	dropmon_ops[i].cmd);
	357	goto out_unreg;
	358	}
	359	}
	360
4ea7e386 NH	361	rc = register_netdevice_notifier(&dropmon_net_notifier);
	362	if (rc < 0) {
	363	printk(KERN_CRIT "Failed to register netdevice notifier\n");
	364	goto out_unreg;
	365	}
	366
9a8afc8d NH	367	rc = 0;
	368
	369	for_each_present_cpu(cpu) {
	370	data = &per_cpu(dm_cpu_data, cpu);
	371	reset_per_cpu_data(data);
	372	INIT_WORK(&data->dm_alert_work, send_dm_alert);
	373	init_timer(&data->send_timer);
	374	data->send_timer.data = cpu;
	375	data->send_timer.function = sched_send_work;
	376	}
4ea7e386	377
9a8afc8d NH	378	goto out;
	379
	380	out_unreg:
	381	genl_unregister_family(&net_drop_monitor_family);
	382	out:
	383	return rc;
	384	}
	385
	386	late_initcall(init_net_drop_monitor);