[VLAN]: Avoid a 4-order allocation.

This patch splits the vlan_group struct into a multi-allocated struct. On
x86_64, the size of the original struct is a little more than 32KB, causing
a 4-order allocation, which is prune to problems caused by buddy-system
external fragmentation conditions.

I couldn't just use vmalloc() because vfree() cannot be called in the
softirq context of the RCU callback.

Signed-off-by: Dan Aloni <da-x@monatomic.org>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Aloni
2007-03-02 20:44:51 -08:00
committed by David S. Miller
parent b5284e5aa9
commit 5c15bdec5c
22 changed files with 102 additions and 80 deletions

View File

@ -70,15 +70,34 @@ extern void vlan_ioctl_set(int (*hook)(void __user *));
* depends on completely exhausting the VLAN identifier space. Thus
* it gives constant time look-up, but in many cases it wastes memory.
*/
#define VLAN_GROUP_ARRAY_LEN 4096
#define VLAN_GROUP_ARRAY_LEN 4096
#define VLAN_GROUP_ARRAY_SPLIT_PARTS 8
#define VLAN_GROUP_ARRAY_PART_LEN (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
struct vlan_group {
int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
struct hlist_node hlist; /* linked list */
struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN];
struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
struct rcu_head rcu;
};
static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, int vlan_id)
{
struct net_device **array;
array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
}
static inline void vlan_group_set_device(struct vlan_group *vg, int vlan_id,
struct net_device *dev)
{
struct net_device **array;
if (!vg)
return;
array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
}
struct vlan_priority_tci_mapping {
unsigned long priority;
unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
@ -160,7 +179,7 @@ static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
return NET_RX_DROP;
}
skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK];
skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
if (skb->dev == NULL) {
dev_kfree_skb_any(skb);