[v2,1/2] batman-adv: BATMAN_V: introduce per hard-iface OGMv2 queues
Commit Message
In preparation for the OGMv2 packet aggregation, hold OGMv2 packets for
up to BATADV_MAX_AGGREGATION_MS milliseconds (100ms) on per
hard-interface queues, before transmitting.
This allows us to later squash multiple OGMs into a single frame
and transmission for reduced overhead.
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
net/batman-adv/bat_v.c | 7 ++
net/batman-adv/bat_v_ogm.c | 152 ++++++++++++++++++++++++++++++++++++-
net/batman-adv/bat_v_ogm.h | 3 +
net/batman-adv/types.h | 15 ++++
4 files changed, 175 insertions(+), 2 deletions(-)
Comments
On Sunday, 4 August 2019 20:06:31 CEST Linus Lüssing wrote:
[...]
> diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
> index fad95ef6..c33041f6 100644
> --- a/net/batman-adv/bat_v_ogm.c
> +++ b/net/batman-adv/bat_v_ogm.c
> @@ -23,6 +23,7 @@
> #include <linux/rcupdate.h>
> #include <linux/skbuff.h>
> #include <linux/slab.h>
> +#include <linux/spinlock.h>
> #include <linux/stddef.h>
> #include <linux/string.h>
> #include <linux/types.h>
Please also include the <linux/lockdep.h> for lockdep_assert_held(...)
Kind regards,
Sven
On Sunday, 4 August 2019 20:06:31 CEST Linus Lüssing wrote:
> +static inline unsigned int batadv_v_ogm_len(struct sk_buff *skb)
> +{
Please drop the inline here.
Kind regards,
Sven
On Sunday, 4 August 2019 20:06:31 CEST Linus Lüssing wrote:
> + * @aggr_len: length of the OGM aggregate (excluding ethernet frame
> + * size)
Did you really mean "ethernet frame size" here? Not ethernet header size? At
least this would match following part of the second patch:
On Sunday, 4 August 2019 20:06:32 CEST Linus Lüssing wrote:
> + skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
> + if (!skb_aggr) {
> + batadv_v_ogm_aggr_list_free(hard_iface);
> + return;
> + }
Kind regards,
Sven
@@ -79,6 +79,7 @@ static int batadv_v_iface_enable(struct batadv_hard_iface *hard_iface)
static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
{
+ batadv_v_ogm_iface_disable(hard_iface);
batadv_v_elp_iface_disable(hard_iface);
}
@@ -1081,6 +1082,12 @@ void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
*/
atomic_set(&hard_iface->bat_v.throughput_override, 0);
atomic_set(&hard_iface->bat_v.elp_interval, 500);
+
+ hard_iface->bat_v.aggr_len = 0;
+ skb_queue_head_init(&hard_iface->bat_v.aggr_list);
+ spin_lock_init(&hard_iface->bat_v.aggr_list_lock);
+ INIT_DELAYED_WORK(&hard_iface->bat_v.aggr_wq,
+ batadv_v_ogm_aggr_work);
}
/**
@@ -23,6 +23,7 @@
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
+#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -76,6 +77,20 @@ struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
return orig_node;
}
+/**
+ * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
+ * @hard_iface: the interface to use to send the OGM
+ */
+static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
+{
+ unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
+
+ /* msecs * [0.9, 1.1] */
+ msecs += prandom_u32() % (msecs / 5) - (msecs / 10);
+ queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
+ msecs_to_jiffies(msecs / 1000));
+}
+
/**
* batadv_v_ogm_start_timer() - restart the OGM sending timer
* @bat_priv: the bat priv with all the soft interface information
@@ -115,6 +130,104 @@ static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
batadv_send_broadcast_skb(skb, hard_iface);
}
+/**
+ * batadv_v_ogm_len() - OGMv2 packet length
+ * @skb: the OGM to check
+ *
+ * Return: Length of the given OGMv2 packet, including tvlv length, excluding
+ * ethernet frame length.
+ */
+static inline unsigned int batadv_v_ogm_len(struct sk_buff *skb)
+{
+ struct batadv_ogm2_packet *ogm_packet;
+
+ ogm_packet = (struct batadv_ogm2_packet *)skb->data;
+ return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
+}
+
+/**
+ * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
+ * @skb: the OGM to check
+ * @hard_iface: the interface to use to send the OGM
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
+ *
+ * Return: True, if the given OGMv2 packet still fits, false otherwise.
+ */
+static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
+ struct batadv_hard_iface *hard_iface)
+{
+ unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
+ BATADV_MAX_AGGREGATION_BYTES);
+ unsigned int ogm_len = batadv_v_ogm_len(skb);
+
+ lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
+
+ return hard_iface->bat_v.aggr_len + ogm_len <= max;
+}
+
+/**
+ * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
+ * @hard_iface: the interface holding the aggregation queue
+ *
+ * Empties the OGMv2 aggregation queue and frees all the skbs it contained.
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
+ */
+static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
+{
+ struct sk_buff *skb;
+
+ lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
+
+ while ((skb = skb_dequeue(&hard_iface->bat_v.aggr_list)))
+ kfree_skb(skb);
+
+ hard_iface->bat_v.aggr_len = 0;
+}
+
+/**
+ * batadv_v_ogm_aggr_send() - flush & send aggregation queue
+ * @hard_iface: the interface with the aggregation queue to flush
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list_lock.
+ */
+static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
+{
+ struct sk_buff *skb;
+
+ lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock);
+
+ while ((skb = skb_dequeue(&hard_iface->bat_v.aggr_list))) {
+ hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
+ batadv_v_ogm_send_to_if(skb, hard_iface);
+ }
+}
+
+/**
+ * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
+ * @skb: the OGM to queue
+ * @hard_iface: the interface to queue the OGM on
+ */
+static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
+ struct batadv_hard_iface *hard_iface)
+{
+ struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+
+ if (!atomic_read(&bat_priv->aggregated_ogms)) {
+ batadv_v_ogm_send_to_if(skb, hard_iface);
+ return;
+ }
+
+ spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
+ if (!batadv_v_ogm_queue_left(skb, hard_iface))
+ batadv_v_ogm_aggr_send(hard_iface);
+
+ hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
+ skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
+ spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
+}
+
/**
* batadv_v_ogm_send() - periodic worker broadcasting the own OGM
* @work: work queue item
@@ -210,7 +323,7 @@ static void batadv_v_ogm_send(struct work_struct *work)
break;
}
- batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
+ batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
batadv_hardif_put(hard_iface);
}
rcu_read_unlock();
@@ -223,6 +336,27 @@ static void batadv_v_ogm_send(struct work_struct *work)
return;
}
+/**
+ * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
+ * @work: work queue item
+ *
+ * Emits aggregated OGM message in regular intervals.
+ */
+void batadv_v_ogm_aggr_work(struct work_struct *work)
+{
+ struct batadv_hard_iface_bat_v *batv;
+ struct batadv_hard_iface *hard_iface;
+
+ batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
+ hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
+
+ spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
+ batadv_v_ogm_aggr_send(hard_iface);
+ spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
+
+ batadv_v_ogm_start_queue_timer(hard_iface);
+}
+
/**
* batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
* @hard_iface: the interface to prepare
@@ -235,11 +369,25 @@ int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
{
struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+ batadv_v_ogm_start_queue_timer(hard_iface);
batadv_v_ogm_start_timer(bat_priv);
return 0;
}
+/**
+ * batadv_v_ogm_iface_disable() - release OGM interface private resources
+ * @hard_iface: interface for which the resources have to be released
+ */
+void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
+{
+ cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
+
+ spin_lock_bh(&hard_iface->bat_v.aggr_list_lock);
+ batadv_v_ogm_aggr_list_free(hard_iface);
+ spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock);
+}
+
/**
* batadv_v_ogm_primary_iface_set() - set a new primary interface
* @primary_iface: the new primary interface
@@ -382,7 +530,7 @@ static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
ogm_forward->ttl, if_incoming->net_dev->name);
- batadv_v_ogm_send_to_if(skb, if_outgoing);
+ batadv_v_ogm_queue_on_if(skb, if_outgoing);
out:
if (orig_ifinfo)
@@ -11,10 +11,13 @@
#include <linux/skbuff.h>
#include <linux/types.h>
+#include <linux/workqueue.h>
int batadv_v_ogm_init(struct batadv_priv *bat_priv);
void batadv_v_ogm_free(struct batadv_priv *bat_priv);
+void batadv_v_ogm_aggr_work(struct work_struct *work);
int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface);
+void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface);
struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
const u8 *addr);
void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface);
@@ -117,6 +117,21 @@ struct batadv_hard_iface_bat_v {
/** @elp_wq: workqueue used to schedule ELP transmissions */
struct delayed_work elp_wq;
+ /** @aggr_wq: workqueue used to transmit queued OGM packets */
+ struct delayed_work aggr_wq;
+
+ /** @aggr_list: queue for to be aggregated OGM packets */
+ struct sk_buff_head aggr_list;
+
+ /**
+ * @aggr_len: length of the OGM aggregate (excluding ethernet frame
+ * size)
+ */
+ unsigned int aggr_len;
+
+ /** @aggr_list_lock: protects aggr_list */
+ spinlock_t aggr_list_lock;
+
/**
* @throughput_override: throughput override to disable link
* auto-detection