From: Jesse Gross Date: Wed, 20 Oct 2010 13:56:05 +0000 (+0000) Subject: vlan: Avoid hash table lookup to find group. X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=65ac6a5fa658b90f1be700c55e7cd72e4611015d;p=linux-beck.git vlan: Avoid hash table lookup to find group. A struct net_device always maps to zero or one vlan groups and we always know the device when we are looking up a group. We currently do a hash table lookup on the device to find the group but it is much simpler to just store a pointer. Signed-off-by: Jesse Gross Signed-off-by: David S. Miller --- diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 494cce866564..4047781da727 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -16,6 +16,7 @@ #ifdef __KERNEL__ #include #include +#include #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header) * that VLAN requires. @@ -114,6 +115,18 @@ static inline void vlan_group_set_device(struct vlan_group *vg, #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) +/* Must be invoked with rcu_read_lock or with RTNL. */ +static inline struct net_device *vlan_find_dev(struct net_device *real_dev, + u16 vlan_id) +{ + struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp); + + if (grp) + return vlan_group_get_device(grp, vlan_id); + + return NULL; +} + extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); extern u16 vlan_dev_vlan_id(const struct net_device *dev); @@ -128,6 +141,12 @@ vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp, unsigned int vlan_tci); #else +static inline struct net_device *vlan_find_dev(struct net_device *real_dev, + u16 vlan_id) +{ + return NULL; +} + static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) { BUG(); diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 2861565a27d9..9c78312ce142 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -942,7 +942,10 @@ struct net_device { /* Protocol specific pointers */ - + +#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) + struct vlan_group *vlgrp; /* VLAN group */ +#endif #ifdef CONFIG_NET_DSA void *dsa_ptr; /* dsa specific data */ #endif diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 54f22d820ef5..f862dccf6bb0 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -44,9 +44,6 @@ int vlan_net_id __read_mostly; -/* Our listing of VLAN group(s) */ -static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE]; - const char vlan_fullname[] = "802.1Q VLAN Support"; const char vlan_version[] = DRV_VERSION; static const char vlan_copyright[] = "Ben Greear "; @@ -59,40 +56,6 @@ static struct packet_type vlan_packet_type __read_mostly = { /* End of global variables definitions. */ -static inline unsigned int vlan_grp_hashfn(unsigned int idx) -{ - return ((idx >> VLAN_GRP_HASH_SHIFT) ^ idx) & VLAN_GRP_HASH_MASK; -} - -/* Must be invoked with RCU read lock (no preempt) */ -static struct vlan_group *__vlan_find_group(struct net_device *real_dev) -{ - struct vlan_group *grp; - struct hlist_node *n; - int hash = vlan_grp_hashfn(real_dev->ifindex); - - hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) { - if (grp->real_dev == real_dev) - return grp; - } - - return NULL; -} - -/* Find the protocol handler. Assumes VID < VLAN_VID_MASK. - * - * Must be invoked with RCU read lock (no preempt) - */ -struct net_device *__find_vlan_dev(struct net_device *real_dev, u16 vlan_id) -{ - struct vlan_group *grp = __vlan_find_group(real_dev); - - if (grp) - return vlan_group_get_device(grp, vlan_id); - - return NULL; -} - static void vlan_group_free(struct vlan_group *grp) { int i; @@ -111,8 +74,6 @@ static struct vlan_group *vlan_group_alloc(struct net_device *real_dev) return NULL; grp->real_dev = real_dev; - hlist_add_head_rcu(&grp->hlist, - &vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]); return grp; } @@ -151,7 +112,7 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) ASSERT_RTNL(); - grp = __vlan_find_group(real_dev); + grp = real_dev->vlgrp; BUG_ON(!grp); /* Take it out of our own structures, but be sure to interlock with @@ -173,11 +134,10 @@ void unregister_vlan_dev(struct net_device *dev, struct list_head *head) if (grp->nr_vlans == 0) { vlan_gvrp_uninit_applicant(real_dev); + rcu_assign_pointer(real_dev->vlgrp, NULL); if (real_dev->features & NETIF_F_HW_VLAN_RX) ops->ndo_vlan_rx_register(real_dev, NULL); - hlist_del_rcu(&grp->hlist); - /* Free the group, after all cpu's are done. */ call_rcu(&grp->rcu, vlan_rcu_free); } @@ -207,7 +167,7 @@ int vlan_check_real_dev(struct net_device *real_dev, u16 vlan_id) return -EOPNOTSUPP; } - if (__find_vlan_dev(real_dev, vlan_id) != NULL) + if (vlan_find_dev(real_dev, vlan_id) != NULL) return -EEXIST; return 0; @@ -222,7 +182,7 @@ int register_vlan_dev(struct net_device *dev) struct vlan_group *grp, *ngrp = NULL; int err; - grp = __vlan_find_group(real_dev); + grp = real_dev->vlgrp; if (!grp) { ngrp = grp = vlan_group_alloc(real_dev); if (!grp) @@ -252,8 +212,11 @@ int register_vlan_dev(struct net_device *dev) vlan_group_set_device(grp, vlan_id, dev); grp->nr_vlans++; - if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX) - ops->ndo_vlan_rx_register(real_dev, ngrp); + if (ngrp) { + if (real_dev->features & NETIF_F_HW_VLAN_RX) + ops->ndo_vlan_rx_register(real_dev, ngrp); + rcu_assign_pointer(real_dev->vlgrp, ngrp); + } if (real_dev->features & NETIF_F_HW_VLAN_FILTER) ops->ndo_vlan_rx_add_vid(real_dev, vlan_id); @@ -264,7 +227,6 @@ out_uninit_applicant: vlan_gvrp_uninit_applicant(real_dev); out_free_group: if (ngrp) { - hlist_del_rcu(&ngrp->hlist); /* Free the group, after all cpu's are done. */ call_rcu(&ngrp->rcu, vlan_rcu_free); } @@ -428,7 +390,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, dev->netdev_ops->ndo_vlan_rx_add_vid(dev, 0); } - grp = __vlan_find_group(dev); + grp = dev->vlgrp; if (!grp) goto out; @@ -746,8 +708,6 @@ err0: static void __exit vlan_cleanup_module(void) { - unsigned int i; - vlan_ioctl_set(NULL); vlan_netlink_fini(); @@ -755,10 +715,6 @@ static void __exit vlan_cleanup_module(void) dev_remove_pack(&vlan_packet_type); - /* This table must be empty if there are no module references left. */ - for (i = 0; i < VLAN_GRP_HASH_SIZE; i++) - BUG_ON(!hlist_empty(&vlan_group_hash[i])); - unregister_pernet_subsys(&vlan_net_ops); rcu_barrier(); /* Wait for completion of call_rcu()'s */ diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h index 8d9503ad01da..db01b3181fdc 100644 --- a/net/8021q/vlan.h +++ b/net/8021q/vlan.h @@ -72,23 +72,6 @@ static inline struct vlan_dev_info *vlan_dev_info(const struct net_device *dev) return netdev_priv(dev); } -#define VLAN_GRP_HASH_SHIFT 5 -#define VLAN_GRP_HASH_SIZE (1 << VLAN_GRP_HASH_SHIFT) -#define VLAN_GRP_HASH_MASK (VLAN_GRP_HASH_SIZE - 1) - -/* Find a VLAN device by the MAC address of its Ethernet device, and - * it's VLAN ID. The default configuration is to have VLAN's scope - * to be box-wide, so the MAC will be ignored. The mac will only be - * looked at if we are configured to have a separate set of VLANs per - * each MAC addressable interface. Note that this latter option does - * NOT follow the spec for VLANs, but may be useful for doing very - * large quantities of VLAN MUX/DEMUX onto FrameRelay or ATM PVCs. - * - * Must be invoked with rcu_read_lock (ie preempt disabled) - * or with RTNL. - */ -struct net_device *__find_vlan_dev(struct net_device *real_dev, u16 vlan_id); - /* found in vlan_dev.c */ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *ptype, struct net_device *orig_dev); diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index f54251edd40d..14e3d1fa07a0 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -158,7 +158,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, vlan_id = vlan_tci & VLAN_VID_MASK; rcu_read_lock(); - vlan_dev = __find_vlan_dev(dev, vlan_id); + vlan_dev = vlan_find_dev(dev, vlan_id); /* If the VLAN device is defined, we use it. * If not, and the VID is 0, it is a 802.1p packet (not