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Diffstat (limited to 'net/core/drop_monitor.c')
-rw-r--r--net/core/drop_monitor.c113
1 files changed, 59 insertions, 54 deletions
diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
index 7f36b38..b856f87 100644
--- a/net/core/drop_monitor.c
+++ b/net/core/drop_monitor.c
@@ -33,22 +33,19 @@
#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 DEFINE_SPINLOCK(trace_state_lock);
+static DEFINE_MUTEX(trace_state_mutex);
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;
+ spinlock_t lock;
+ struct sk_buff *skb;
+ struct work_struct dm_alert_work;
+ struct timer_list send_timer;
};
struct dm_hw_stat_delta {
@@ -74,56 +71,59 @@ 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)
+static struct sk_buff *reset_per_cpu_data(struct per_cpu_dm_data *data)
{
size_t al;
struct net_dm_alert_msg *msg;
struct nlattr *nla;
+ struct sk_buff *skb;
+ unsigned long flags;
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);
+ skb = genlmsg_new(al, GFP_KERNEL);
+
+ if (skb) {
+ genlmsg_put(skb, 0, 0, &net_drop_monitor_family,
+ 0, NET_DM_CMD_ALERT);
+ nla = nla_reserve(skb, NLA_UNSPEC,
+ sizeof(struct net_dm_alert_msg));
+ msg = nla_data(nla);
+ memset(msg, 0, al);
+ } else {
+ mod_timer(&data->send_timer, jiffies + HZ / 10);
+ }
+
+ spin_lock_irqsave(&data->lock, flags);
+ swap(data->skb, skb);
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ return skb;
}
-static void send_dm_alert(struct work_struct *unused)
+static void send_dm_alert(struct work_struct *work)
{
struct sk_buff *skb;
- struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
+ struct per_cpu_dm_data *data;
- /*
- * Grab the skb we're about to send
- */
- skb = data->skb;
+ data = container_of(work, struct per_cpu_dm_data, dm_alert_work);
- /*
- * Replace it with a new one
- */
- reset_per_cpu_data(data);
-
- /*
- * Ship it!
- */
- genlmsg_multicast(skb, 0, NET_DM_GRP_ALERT, GFP_KERNEL);
+ skb = reset_per_cpu_data(data);
+ if (skb)
+ 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
+ * hysteresis period.
*/
-static void sched_send_work(unsigned long unused)
+static void sched_send_work(unsigned long _data)
{
- struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
+ struct per_cpu_dm_data *data = (struct per_cpu_dm_data *)_data;
schedule_work(&data->dm_alert_work);
}
@@ -134,17 +134,19 @@ static void trace_drop_common(struct sk_buff *skb, void *location)
struct nlmsghdr *nlh;
struct nlattr *nla;
int i;
- struct per_cpu_dm_data *data = &__get_cpu_var(dm_cpu_data);
+ struct sk_buff *dskb;
+ struct per_cpu_dm_data *data;
+ unsigned long flags;
+ local_irq_save(flags);
+ data = &__get_cpu_var(dm_cpu_data);
+ spin_lock(&data->lock);
+ dskb = data->skb;
- if (!atomic_add_unless(&data->dm_hit_count, -1, 0)) {
- /*
- * we're already at zero, discard this hit
- */
+ if (!dskb)
goto out;
- }
- nlh = (struct nlmsghdr *)data->skb->data;
+ nlh = (struct nlmsghdr *)dskb->data;
nla = genlmsg_data(nlmsg_data(nlh));
msg = nla_data(nla);
for (i = 0; i < msg->entries; i++) {
@@ -153,11 +155,12 @@ static void trace_drop_common(struct sk_buff *skb, void *location)
goto out;
}
}
-
+ if (msg->entries == dm_hit_limit)
+ goto out;
/*
* We need to create a new entry
*/
- __nla_reserve_nohdr(data->skb, sizeof(struct net_dm_drop_point));
+ __nla_reserve_nohdr(dskb, 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;
@@ -165,11 +168,11 @@ static void trace_drop_common(struct sk_buff *skb, void *location)
if (!timer_pending(&data->send_timer)) {
data->send_timer.expires = jiffies + dm_delay * HZ;
- add_timer_on(&data->send_timer, smp_processor_id());
+ add_timer(&data->send_timer);
}
out:
- return;
+ spin_unlock_irqrestore(&data->lock, flags);
}
static void trace_kfree_skb_hit(void *ignore, struct sk_buff *skb, void *location)
@@ -213,7 +216,7 @@ static int set_all_monitor_traces(int state)
struct dm_hw_stat_delta *new_stat = NULL;
struct dm_hw_stat_delta *temp;
- spin_lock(&trace_state_lock);
+ mutex_lock(&trace_state_mutex);
if (state == trace_state) {
rc = -EAGAIN;
@@ -252,7 +255,7 @@ static int set_all_monitor_traces(int state)
rc = -EINPROGRESS;
out_unlock:
- spin_unlock(&trace_state_lock);
+ mutex_unlock(&trace_state_mutex);
return rc;
}
@@ -295,12 +298,12 @@ static int dropmon_net_event(struct notifier_block *ev_block,
new_stat->dev = dev;
new_stat->last_rx = jiffies;
- spin_lock(&trace_state_lock);
+ mutex_lock(&trace_state_mutex);
list_add_rcu(&new_stat->list, &hw_stats_list);
- spin_unlock(&trace_state_lock);
+ mutex_unlock(&trace_state_mutex);
break;
case NETDEV_UNREGISTER:
- spin_lock(&trace_state_lock);
+ mutex_lock(&trace_state_mutex);
list_for_each_entry_safe(new_stat, tmp, &hw_stats_list, list) {
if (new_stat->dev == dev) {
new_stat->dev = NULL;
@@ -311,7 +314,7 @@ static int dropmon_net_event(struct notifier_block *ev_block,
}
}
}
- spin_unlock(&trace_state_lock);
+ mutex_unlock(&trace_state_mutex);
break;
}
out:
@@ -367,13 +370,15 @@ static int __init init_net_drop_monitor(void)
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.data = (unsigned long)data;
data->send_timer.function = sched_send_work;
+ spin_lock_init(&data->lock);
+ reset_per_cpu_data(data);
}
+
goto out;
out_unreg:
generated by cgit v1.1 at 2024-04-28 19:46:42 +0000