From 67727184f28c38d06013c6659560bb046c1d9f9c Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 26 Mar 2008 16:27:22 -0700 Subject: [VLAN]: Reduce memory consumed by vlan_groups Currently each vlan_groupd contains 8 pointers on arrays with 512 pointers on struct net_device each :) Such a construction "in many cases ... wastes memory". My proposal is to allow for some of these arrays pointers be NULL, meaning that there are no devices in it. When a new device is added to the vlan_group, the appropriate array is allocated. The check in vlan_group_get_device's is safe, since the pointer vg->vlan_devices_arrays[x] can only switch from NULL to not-NULL. The vlan_group_prealloc_vid() is guarded with rtnl lock and is also safe. I've checked (I hope that) all the places, that use these arrays and found, that the register_vlan_dev is the only place, that can put a vlan device on an empty vlan_group. Rough calculations shows, that after the patch a setup with a single vlan dev (or up to 512 vlans with sequential vids) will occupy approximately 8 times less memory. The question I have is - does this patch makes sense, or a totally new structures are required to store the vlan_devs? Signed-off-by: Pavel Emelyanov Signed-off-by: Patrick McHardy --- include/linux/if_vlan.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/if_vlan.h') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index 79504b22a932..edd55af7ebd6 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -93,7 +93,7 @@ static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, { 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]; + return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL; } static inline void vlan_group_set_device(struct vlan_group *vg, -- cgit v1.2.3 From a9fde2607895667823e9d1172fc193087125ef68 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Wed, 16 Apr 2008 00:48:04 -0700 Subject: [VLAN]: Tag vlan_group_device with net device, not ifindex. Currently vlan group is searched using one key - the ifindex. We'll have to lookup the vlan_group by two keys - ifindex and net. Turning the vlan_group lookup key to struct net_device pointer will make this process easier. Besides, this will eliminate one more place in the networking, that assumes that indexes are unique in the kernel. Signed-off-by: Pavel Emelyanov Acked-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/if_vlan.h | 4 +++- net/8021q/vlan.c | 22 +++++++++++----------- 2 files changed, 14 insertions(+), 12 deletions(-) (limited to 'include/linux/if_vlan.h') diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h index edd55af7ebd6..15ace02b7b24 100644 --- a/include/linux/if_vlan.h +++ b/include/linux/if_vlan.h @@ -81,7 +81,9 @@ extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); #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 net_device *real_dev; /* The ethernet(like) device + * the vlan is attached to. + */ unsigned int nr_vlans; struct hlist_node hlist; /* linked list */ struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS]; diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index 5975ec3be7f3..cf8d810a130d 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -65,14 +65,14 @@ static inline unsigned int vlan_grp_hashfn(unsigned int idx) } /* Must be invoked with RCU read lock (no preempt) */ -static struct vlan_group *__vlan_find_group(int real_dev_ifindex) +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); + int hash = vlan_grp_hashfn(real_dev->ifindex); hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) { - if (grp->real_dev_ifindex == real_dev_ifindex) + if (grp->real_dev == real_dev) return grp; } @@ -86,7 +86,7 @@ static struct vlan_group *__vlan_find_group(int real_dev_ifindex) struct net_device *__find_vlan_dev(struct net_device *real_dev, unsigned short VID) { - struct vlan_group *grp = __vlan_find_group(real_dev->ifindex); + struct vlan_group *grp = __vlan_find_group(real_dev); if (grp) return vlan_group_get_device(grp, VID); @@ -103,7 +103,7 @@ static void vlan_group_free(struct vlan_group *grp) kfree(grp); } -static struct vlan_group *vlan_group_alloc(int ifindex) +static struct vlan_group *vlan_group_alloc(struct net_device *real_dev) { struct vlan_group *grp; @@ -111,9 +111,9 @@ static struct vlan_group *vlan_group_alloc(int ifindex) if (!grp) return NULL; - grp->real_dev_ifindex = ifindex; + grp->real_dev = real_dev; hlist_add_head_rcu(&grp->hlist, - &vlan_group_hash[vlan_grp_hashfn(ifindex)]); + &vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]); return grp; } @@ -151,7 +151,7 @@ void unregister_vlan_dev(struct net_device *dev) ASSERT_RTNL(); - grp = __vlan_find_group(real_dev->ifindex); + grp = __vlan_find_group(real_dev); BUG_ON(!grp); vlan_proc_rem_dev(dev); @@ -246,9 +246,9 @@ int register_vlan_dev(struct net_device *dev) struct vlan_group *grp, *ngrp = NULL; int err; - grp = __vlan_find_group(real_dev->ifindex); + grp = __vlan_find_group(real_dev); if (!grp) { - ngrp = grp = vlan_group_alloc(real_dev->ifindex); + ngrp = grp = vlan_group_alloc(real_dev); if (!grp) return -ENOBUFS; } @@ -412,7 +412,7 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event, goto out; } - grp = __vlan_find_group(dev->ifindex); + grp = __vlan_find_group(dev); if (!grp) goto out; -- cgit v1.2.3