diff options
| author | Eric Dumazet <edumazet@google.com> | 2018-05-02 20:25:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-03 11:28:50 -0400 |
| commit | 114f39feab360e6c7b0c4238697f223444d662a1 (patch) | |
| tree | 9d8ec8ad5e398508a564259c6a5f646792545c79 /net | |
| parent | eb80ca476ec11f67a62691a93604b405ffc7d80c (diff) | |
| download | linux-0-day-114f39feab360e6c7b0c4238697f223444d662a1.tar.gz linux-0-day-114f39feab360e6c7b0c4238697f223444d662a1.tar.xz | |
tcp: restore autocorking
When adding rb-tree for TCP retransmit queue, we inadvertently broke
TCP autocorking.
tcp_should_autocork() should really check if the rtx queue is not empty.
Tested:
Before the fix :
$ nstat -n;./netperf -H 10.246.7.152 -Cc -- -m 500;nstat | grep AutoCork
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.246.7.152 () port 0 AF_INET
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB
540000 262144 500 10.00 2682.85 2.47 1.59 3.618 2.329
TcpExtTCPAutoCorking 33 0.0
// Same test, but forcing TCP_NODELAY
$ nstat -n;./netperf -H 10.246.7.152 -Cc -- -D -m 500;nstat | grep AutoCork
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.246.7.152 () port 0 AF_INET : nodelay
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB
540000 262144 500 10.00 1408.75 2.44 2.96 6.802 8.259
TcpExtTCPAutoCorking 1 0.0
After the fix :
$ nstat -n;./netperf -H 10.246.7.152 -Cc -- -m 500;nstat | grep AutoCork
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.246.7.152 () port 0 AF_INET
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB
540000 262144 500 10.00 5472.46 2.45 1.43 1.761 1.027
TcpExtTCPAutoCorking 361293 0.0
// With TCP_NODELAY option
$ nstat -n;./netperf -H 10.246.7.152 -Cc -- -D -m 500;nstat | grep AutoCork
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.246.7.152 () port 0 AF_INET : nodelay
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. 10^6bits/s % S % S us/KB us/KB
540000 262144 500 10.00 5454.96 2.46 1.63 1.775 1.174
TcpExtTCPAutoCorking 315448 0.0
Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Michael Wenig <mwenig@vmware.com>
Tested-by: Michael Wenig <mwenig@vmware.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Michael Wenig <mwenig@vmware.com>
Tested-by: Michael Wenig <mwenig@vmware.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 44be7f43455e4..c9d00ef54deca 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -697,7 +697,7 @@ static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb, { return skb->len < size_goal && sock_net(sk)->ipv4.sysctl_tcp_autocorking && - skb != tcp_write_queue_head(sk) && + !tcp_rtx_queue_empty(sk) && refcount_read(&sk->sk_wmem_alloc) > skb->truesize; } |