@@ -47,6 +47,7 @@
#include <uapi/linux/if_bonding.h>
#include <uapi/linux/pkt_cls.h>
#include <linux/hashtable.h>
+#include <linux/rbtree.h>
struct netpoll_info;
struct device;
@@ -218,12 +219,16 @@ struct netdev_hw_addr {
int sync_cnt;
int refcount;
int synced;
+ struct rb_node node;
struct rcu_head rcu_head;
};
struct netdev_hw_addr_list {
struct list_head list;
int count;
+
+ /* Auxiliary tree for faster lookup when modifying the structure. */
+ struct rb_root tree_root;
};
#define netdev_hw_addr_list_count(l) ((l)->count)
@@ -12,6 +12,70 @@
#include <linux/export.h>
#include <linux/list.h>
+/* Lookup for an address in the list using the rbtree.
+ * The return value is always a valid pointer.
+ * If the address exists, `*ret` is non-null and the address can be retrieved using
+ *
+ * container_of(*ret, struct netdev_hw_addr, node)
+ *
+ * Otherwise, `ret` can be used with `parent` as an insertion point
+ * when calling `__hw_addr_insert_address_to_tree`.
+ *
+ * Must only be called when holding the netdevice's spinlock.
+ *
+ * @ignore_zero_addr_type if true and `addr_type` is zero,
+ * disregard addr_type when matching;
+ */
+static struct rb_node **__hw_addr_tree_address_lookup(struct netdev_hw_addr_list *list,
+ const unsigned char *addr,
+ int addr_len,
+ unsigned char addr_type,
+ bool ignore_zero_addr_type,
+ struct rb_node **parent)
+{
+ struct rb_node **node = &list->tree_root.rb_node, *_parent;
+
+ while (*node) {
+ struct netdev_hw_addr *data = container_of(*node, struct netdev_hw_addr, node);
+ int result;
+
+ result = memcmp(addr, data->addr, addr_len);
+
+ if (!result && (ignore_zero_addr_type && !addr_type))
+ result = memcmp(&addr_type, &data->type, sizeof(addr_type));
+
+ _parent = *node;
+ if (result < 0)
+ node = &(*node)->rb_left;
+ else if (result > 0)
+ node = &(*node)->rb_right;
+ else
+ break;
+ }
+
+ if (parent)
+ *parent = _parent;
+ return node;
+}
+
+
+static int __hw_addr_insert_address_to_tree(struct netdev_hw_addr_list *list,
+ struct netdev_hw_addr *ha,
+ int addr_len,
+ struct rb_node **insertion_point,
+ struct rb_node *parent)
+{
+ /* Figure out where to put new node */
+ if (!insertion_point || !parent)
+ insertion_point = __hw_addr_tree_address_lookup(list, ha->addr, addr_len, ha->type, false, &parent);
+
+ /* Add new node and rebalance tree. */
+ rb_link_node(&ha->node, parent, insertion_point);
+ rb_insert_color(&ha->node, &list->tree_root);
+
+ return true;
+}
+
/*
* General list handling functions
*/
@@ -19,7 +83,9 @@
static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
const unsigned char *addr, int addr_len,
unsigned char addr_type, bool global,
- bool sync)
+ bool sync,
+ struct rb_node **insertion_point,
+ struct rb_node *parent)
{
struct netdev_hw_addr *ha;
int alloc_size;
@@ -36,6 +102,10 @@ static int __hw_addr_create_ex(struct netdev_hw_addr_list *list,
ha->global_use = global;
ha->synced = sync ? 1 : 0;
ha->sync_cnt = 0;
+
+ /* Insert node to hash table for quicker lookups during modification */
+ __hw_addr_insert_address_to_tree(list, ha, addr_len, insertion_point, parent);
+
list_add_tail_rcu(&ha->list, &list->list);
list->count++;
@@ -47,34 +117,36 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
unsigned char addr_type, bool global, bool sync,
int sync_count)
{
+ struct rb_node *insert_parent = NULL;
struct netdev_hw_addr *ha;
+ struct rb_node **ha_node;
if (addr_len > MAX_ADDR_LEN)
return -EINVAL;
- list_for_each_entry(ha, &list->list, list) {
- if (ha->type == addr_type &&
- !memcmp(ha->addr, addr, addr_len)) {
- if (global) {
- /* check if addr is already used as global */
- if (ha->global_use)
- return 0;
- else
- ha->global_use = true;
- }
- if (sync) {
- if (ha->synced && sync_count)
- return -EEXIST;
- else
- ha->synced++;
- }
- ha->refcount++;
- return 0;
+ ha_node = __hw_addr_tree_address_lookup(list, addr, addr_len,
+ addr_type, false, &insert_parent);
+ if (*ha_node) {
+ ha = container_of(*ha_node, struct netdev_hw_addr, node);
+ if (global) {
+ /* check if addr is already used as global */
+ if (ha->global_use)
+ return 0;
+ else
+ ha->global_use = true;
}
+ if (sync) {
+ if (ha->synced && sync_count)
+ return -EEXIST;
+ else
+ ha->synced++;
+ }
+ ha->refcount++;
+ return 0;
}
return __hw_addr_create_ex(list, addr, addr_len, addr_type, global,
- sync);
+ sync, ha_node, insert_parent);
}
static int __hw_addr_add(struct netdev_hw_addr_list *list,
@@ -103,6 +175,8 @@ static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
if (--ha->refcount)
return 0;
+
+ rb_erase(&ha->node, &list->tree_root);
list_del_rcu(&ha->list);
kfree_rcu(ha, rcu_head);
list->count--;
@@ -114,13 +188,14 @@ static int __hw_addr_del_ex(struct netdev_hw_addr_list *list,
unsigned char addr_type, bool global, bool sync)
{
struct netdev_hw_addr *ha;
+ struct rb_node **ha_node;
- list_for_each_entry(ha, &list->list, list) {
- if (!memcmp(ha->addr, addr, addr_len) &&
- (ha->type == addr_type || !addr_type))
- return __hw_addr_del_entry(list, ha, global, sync);
- }
- return -ENOENT;
+ ha_node = __hw_addr_tree_address_lookup(list, addr, addr_len, addr_type, true, NULL);
+ if (*ha_node == NULL)
+ return -ENOENT;
+
+ ha = container_of(*ha_node, struct netdev_hw_addr, node);
+ return __hw_addr_del_entry(list, ha, global, sync);
}
static int __hw_addr_del(struct netdev_hw_addr_list *list,
@@ -418,6 +493,7 @@ void __hw_addr_init(struct netdev_hw_addr_list *list)
{
INIT_LIST_HEAD(&list->list);
list->count = 0;
+ list->tree_root = RB_ROOT;
}
EXPORT_SYMBOL(__hw_addr_init);
@@ -552,19 +628,20 @@ EXPORT_SYMBOL(dev_addr_del);
*/
int dev_uc_add_excl(struct net_device *dev, const unsigned char *addr)
{
- struct netdev_hw_addr *ha;
+ struct rb_node *insert_parent = NULL;
+ struct rb_node **ha_node = NULL;
int err;
netif_addr_lock_bh(dev);
- list_for_each_entry(ha, &dev->uc.list, list) {
- if (!memcmp(ha->addr, addr, dev->addr_len) &&
- ha->type == NETDEV_HW_ADDR_T_UNICAST) {
- err = -EEXIST;
- goto out;
- }
+ ha_node = __hw_addr_tree_address_lookup(&dev->uc, addr, dev->addr_len,
+ NETDEV_HW_ADDR_T_UNICAST, false, &insert_parent);
+ if (*ha_node) {
+ err = -EEXIST;
+ goto out;
}
+
err = __hw_addr_create_ex(&dev->uc, addr, dev->addr_len,
- NETDEV_HW_ADDR_T_UNICAST, true, false);
+ NETDEV_HW_ADDR_T_UNICAST, true, false, ha_node, insert_parent);
if (!err)
__dev_set_rx_mode(dev);
out:
@@ -745,19 +822,19 @@ EXPORT_SYMBOL(dev_uc_init);
*/
int dev_mc_add_excl(struct net_device *dev, const unsigned char *addr)
{
- struct netdev_hw_addr *ha;
+ struct rb_node *insert_parent = NULL;
+ struct rb_node **ha_node;
int err;
netif_addr_lock_bh(dev);
- list_for_each_entry(ha, &dev->mc.list, list) {
- if (!memcmp(ha->addr, addr, dev->addr_len) &&
- ha->type == NETDEV_HW_ADDR_T_MULTICAST) {
- err = -EEXIST;
- goto out;
- }
+ ha_node = __hw_addr_tree_address_lookup(&dev->mc, addr, dev->addr_len,
+ NETDEV_HW_ADDR_T_MULTICAST, false, &insert_parent);
+ if (*ha_node) {
+ err = -EEXIST;
+ goto out;
}
err = __hw_addr_create_ex(&dev->mc, addr, dev->addr_len,
- NETDEV_HW_ADDR_T_MULTICAST, true, false);
+ NETDEV_HW_ADDR_T_MULTICAST, true, false, ha_node, insert_parent);
if (!err)
__dev_set_rx_mode(dev);
out:
When a bond have a massive amount of VLANs with IPv6 addresses, performance of changing link state, attaching a VRF, changing an IPv6 address, etc. go down dramtically. The source of most of the slow down is the `dev_addr_lists.c` module, which mainatins a linked list of HW addresses. When using IPv6, this list grows for each IPv6 address added on a VLAN, since each IPv6 address has a multicast HW address associated with it. When performing any modification to the involved links, this list is traversed many times, often for nothing, all while holding the RTNL lock. Instead, this patch adds an auxilliary rbtree which cuts down traversal time significantly. Performance can be seen with the following script: #!/bin/bash ip netns del test || true 2>/dev/null ip netns add test echo 1 | ip netns exec test tee /proc/sys/net/ipv6/conf/all/keep_addr_on_down > /dev/null set -e ip -n test link add foo type veth peer name bar ip -n test link add b1 type bond ip -n test link add florp type vrf table 10 ip -n test link set bar master b1 ip -n test link set foo up ip -n test link set bar up ip -n test link set b1 up ip -n test link set florp up VLAN_COUNT=1500 BASE_DEV=b1 echo Creating vlans ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link add link $BASE_DEV name foo.\$i type vlan id \$i; done" echo Bringing them up ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link set foo.\$i up; done" echo Assiging IPv6 Addresses ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test address add dev foo.\$i 2000::\$i/64; done" echo Attaching to VRF ip netns exec test time -p bash -c "for i in \$(seq 1 $VLAN_COUNT); do ip -n test link set foo.\$i master florp; done" On an Intel(R) Xeon(R) CPU E5-2650 v3 @ 2.30GHz machine, the performance before the patch is (truncated): Creating vlans real 108.35 Bringing them up real 4.96 Assiging IPv6 Addresses real 19.22 Attaching to VRF real 458.84 After the patch: Creating vlans real 5.59 Bringing them up real 5.07 Assiging IPv6 Addresses real 5.64 Attaching to VRF real 25.37 Cc: David S. Miller <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Lu Wei <luwei32@huawei.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Taehee Yoo <ap420073@gmail.com> Signed-off-by: Gilad Naaman <gnaaman@drivenets.com> --- include/linux/netdevice.h | 5 ++ net/core/dev_addr_lists.c | 161 ++++++++++++++++++++++++++++---------- 2 files changed, 124 insertions(+), 42 deletions(-)