rps: optimize rps_get_cpu()
optimize rps_get_cpu().
don't initialize ports when we can get the ports. one memory access
for ports than two.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index a4a7c36..4d43f1a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2229,7 +2229,11 @@
int cpu = -1;
u8 ip_proto;
u16 tcpu;
- u32 addr1, addr2, ports, ihl;
+ u32 addr1, addr2, ihl;
+ union {
+ u32 v32;
+ u16 v16[2];
+ } ports;
if (skb_rx_queue_recorded(skb)) {
u16 index = skb_get_rx_queue(skb);
@@ -2275,7 +2279,6 @@
default:
goto done;
}
- ports = 0;
switch (ip_proto) {
case IPPROTO_TCP:
case IPPROTO_UDP:
@@ -2285,25 +2288,20 @@
case IPPROTO_SCTP:
case IPPROTO_UDPLITE:
if (pskb_may_pull(skb, (ihl * 4) + 4)) {
- __be16 *hports = (__be16 *) (skb->data + (ihl * 4));
- u32 sport, dport;
-
- sport = (__force u16) hports[0];
- dport = (__force u16) hports[1];
- if (dport < sport)
- swap(sport, dport);
- ports = (sport << 16) + dport;
+ ports.v32 = * (__force u32 *) (skb->data + (ihl * 4));
+ if (ports.v16[1] < ports.v16[0])
+ swap(ports.v16[0], ports.v16[1]);
+ break;
}
- break;
-
default:
+ ports.v32 = 0;
break;
}
/* get a consistent hash (same value on both flow directions) */
if (addr2 < addr1)
swap(addr1, addr2);
- skb->rxhash = jhash_3words(addr1, addr2, ports, hashrnd);
+ skb->rxhash = jhash_3words(addr1, addr2, ports.v32, hashrnd);
if (!skb->rxhash)
skb->rxhash = 1;