lkml.org 
[lkml]   [2006]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 3/7] [I/OAT] Don't offload copies for loopback traffic
Date
Local traffic (loopback) is generally in cache anyway, and the overhead
cost of offloading the copy is worse than just doing it with the CPU.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
---

net/ipv4/tcp.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 36f6b64..7971e73 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1107,6 +1107,7 @@ int tcp_recvmsg(struct kiocb *iocb, stru
int copied_early = 0;
int available = 0;
struct sk_buff *skb;
+ struct dst_entry *dst;

lock_sock(sk);

@@ -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)) &&
(len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
!sysctl_tcp_low_latency && __get_cpu_var(softnet_data).net_dma) {
preempt_enable_no_resched();
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-08-16 02:49    [W:0.107 / U:0.840 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site