diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-04-19 20:29:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-25 22:26:28 -0700 |
| commit | 27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26 (patch) | |
| tree | 5a267e40f9b94014be38dad5de0a52b6628834e0 /net/ipv4/ipmr.c | |
| parent | be8bd86321fa7f06359d866ef61fb4d2f3e9dce9 (diff) | |
| download | lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.tar.gz lwn-27a884dc3cb63b93c2b3b643f5b31eed5f8a4d26.zip | |
[SK_BUFF]: Convert skb->tail to sk_buff_data_t
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)
Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ipmr.c')
| -rw-r--r-- | net/ipv4/ipmr.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c index 50d0b301380e..ea0a491dce92 100644 --- a/net/ipv4/ipmr.c +++ b/net/ipv4/ipmr.c @@ -513,7 +513,8 @@ static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c) struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr)); if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) { - nlh->nlmsg_len = skb->tail - (u8*)nlh; + nlh->nlmsg_len = (skb_tail_pointer(skb) - + (u8 *)nlh); } else { nlh->nlmsg_type = NLMSG_ERROR; nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr)); @@ -580,7 +581,7 @@ static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert) * Copy the IP header */ - skb_set_network_header(skb, skb->tail - skb->data); + skb->network_header = skb->tail; skb_put(skb, ihl); memcpy(skb->data,pkt->data,ihl); ip_hdr(skb)->protocol = 0; /* Flag to the kernel this is a route add */ @@ -1544,7 +1545,7 @@ ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm) int ct; struct rtnexthop *nhp; struct net_device *dev = vif_table[c->mfc_parent].dev; - u8 *b = skb->tail; + u8 *b = skb_tail_pointer(skb); struct rtattr *mp_head; if (dev) @@ -1564,7 +1565,7 @@ ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm) } } mp_head->rta_type = RTA_MULTIPATH; - mp_head->rta_len = skb->tail - (u8*)mp_head; + mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head; rtm->rtm_type = RTN_MULTICAST; return 1; |