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| author |   David S. Miller <davem@davemloft.net> | 2008-07-15 03:47:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-07-17 19:21:13 -0700 |
| commit | 8f0f2223cc08a5ae9a77f40edfe02e8a9f1abd77 (patch) | |
| tree | 48185f0e8c5a0d220e33a98fe4ac9b323e25579e /net | |
| parent | mac80211: Reimplement WME using ->select_queue(). (diff) | |
| download | linux-dev-8f0f2223cc08a5ae9a77f40edfe02e8a9f1abd77.tar.xz linux-dev-8f0f2223cc08a5ae9a77f40edfe02e8a9f1abd77.zip | |
net: Implement simple sw TX hashing.
It just xor hashes over IPv4/IPv6 addresses and ports of transport.
The only assumption it makes is that skb_network_header() is set
correctly.
With bug fixes from Eric Dumazet.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/dev.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 7ca9564d2f44..467bfb325123 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -121,6 +121,9 @@ #include <linux/ctype.h> #include <linux/if_arp.h> #include <linux/if_vlan.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/in.h> #include "net-sysfs.h" @@ -1665,6 +1668,53 @@ out_kfree_skb: * --BLG */ +static u16 simple_tx_hash(struct net_device *dev, struct sk_buff *skb) +{ + u32 *addr, *ports, hash, ihl; + u8 ip_proto; + int alen; + + switch (skb->protocol) { + case __constant_htons(ETH_P_IP): + ip_proto = ip_hdr(skb)->protocol; + addr = &ip_hdr(skb)->saddr; + ihl = ip_hdr(skb)->ihl; + alen = 2; + break; + case __constant_htons(ETH_P_IPV6): + ip_proto = ipv6_hdr(skb)->nexthdr; + addr = &ipv6_hdr(skb)->saddr.s6_addr32[0]; + ihl = (40 >> 2); + alen = 8; + break; + default: + return 0; + } + + ports = (u32 *) (skb_network_header(skb) + (ihl * 4)); + + hash = 0; + while (alen--) + hash ^= *addr++; + + switch (ip_proto) { + case IPPROTO_TCP: + case IPPROTO_UDP: + case IPPROTO_DCCP: + case IPPROTO_ESP: + case IPPROTO_AH: + case IPPROTO_SCTP: + case IPPROTO_UDPLITE: + hash ^= *ports; + break; + + default: + break; + } + + return hash % dev->real_num_tx_queues; +} + static struct netdev_queue *dev_pick_tx(struct net_device *dev, struct sk_buff *skb) { @@ -1672,6 +1722,8 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, if (dev->select_queue) queue_index = dev->select_queue(dev, skb); + else if (dev->real_num_tx_queues > 1) + queue_index = simple_tx_hash(dev, skb); skb_set_queue_mapping(skb, queue_index); return netdev_get_tx_queue(dev, queue_index); |