Commit a8d764b9 authored by Junchang Wang's avatar Junchang Wang Committed by David S. Miller

pktgen: adding prefetchw() call

We know for sure pktgen is going to write skb->data right after
*_alloc_skb, causing unnecessary cache misses.

Idea is to add a prefetchw() call to prefetch the first cache line
indicated by skb->data. On systems with Adjacent Cache Line Prefetch,
it's probably two cache lines are prefetched.

With this patch, pktgen on Intel SR1625 server with two E5530
quad-core processors and a single ixgbe-based NIC went from 8.63Mpps
to 9.03Mpps, with 4.6% improvement.
Signed-off-by: default avatarJunchang Wang <junchangwang@gmail.com>
Acked-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4afb7527
......@@ -2660,6 +2660,7 @@ static struct sk_buff *fill_packet_ipv4(struct net_device *odev,
sprintf(pkt_dev->result, "No memory");
return NULL;
}
prefetchw(skb->data);
skb_reserve(skb, datalen);
......@@ -3007,6 +3008,7 @@ static struct sk_buff *fill_packet_ipv6(struct net_device *odev,
sprintf(pkt_dev->result, "No memory");
return NULL;
}
prefetchw(skb->data);
skb_reserve(skb, 16);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment