[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>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/net/cxgb3/cxgb3_offload.c b/drivers/net/cxgb3/cxgb3_offload.c
index b2cf5f6feb4a..f6ed033efb56 100644
--- a/drivers/net/cxgb3/cxgb3_offload.c
+++ b/drivers/net/cxgb3/cxgb3_offload.c
@@ -160,14 +160,16 @@ static struct net_device *get_iff_from_mac(struct adapter *adapter,
         int i;
 
         for_each_port(adapter, i) {
-                const struct vlan_group *grp;
+                struct vlan_group *grp;
                 struct net_device *dev = adapter->port[i];
                 const struct port_info *p = netdev_priv(dev);
 
                 if (!memcmp(dev->dev_addr, mac, ETH_ALEN)) {
                         if (vlan && vlan != VLAN_VID_MASK) {
                                 grp = p->vlan_grp;
-                                dev = grp ? grp->vlan_devices[vlan] : NULL;
+                                dev = NULL;
+                                if (grp)
+                                        dev = vlan_group_get_device(grp, vlan);
                         } else
                                 while (dev->master)
                                         dev = dev->master;