Re: [PATCH 3/7] [I/OAT] Don't offload copies for loopback traffic
From: Andi Kleen <hidden>
Date: 2006-08-18 17:09:14
Also in:
lkml
quoted hunk ↗ jump to hunk
@@ -1136,7 +1137,8 @@ int tcp_recvmsg(struct kiocb *iocb, stru skb = skb_peek_tail(&sk->sk_receive_queue); if (skb) available = TCP_SKB_CB(skb)->seq + skb->len - (*seq); - if ((available < target) && + dst = __sk_dst_get(sk); + if ((available < target) && (!dst || (dst->dev != &loopback_dev)) &&
You just added another potential cache miss to a critical path. A bit flag in the socket would be better. But is it really worth this ugly special case? -Andi