path: root/net/ipv4/tcp_timer.c
diff options
authorLawrence Brakmo <brakmo@fb.com>2016-09-27 19:03:37 -0700
committerDavid S. Miller <davem@davemloft.net>2016-09-28 07:52:34 -0400
commit3acf3ec3f4b0fd4263989f2e4227bbd1c42b5fe1 (patch)
treecdc67656dc5d6ea9bc76ed3e2cd80b3614065d8d /net/ipv4/tcp_timer.c
parentnet/sched: pkt_cls: change tc actions order to be as the user sets (diff)
tcp: Change txhash on every SYN and RTO retransmit
The current code changes txhash (flowlables) on every retransmitted SYN/ACK, but only after the 2nd retransmitted SYN and only after tcp_retries1 RTO retransmits. With this patch: 1) txhash is changed with every SYN retransmits 2) txhash is changed with every RTO. The result is that we can start re-routing around failed (or very congested paths) as soon as possible. Otherwise application health checks may fail and the connection may be terminated before we start to change txhash. v4: Removed sysctl, txhash is changed for all RTOs v3: Removed text saying default value of sysctl is 0 (it is 100) v2: Added sysctl documentation and cleaned code Tested with packetdrill tests Signed-off-by: Lawrence Brakmo <brakmo@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index f712b411f6ed..3ea1cf804748 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -192,6 +192,8 @@ static int tcp_write_timeout(struct sock *sk)
if (tp->syn_data && icsk->icsk_retransmits == 1)
+ } else if (!tp->syn_data && !tp->syn_fastopen) {
+ sk_rethink_txhash(sk);
retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
syn_set = true;
@@ -213,6 +215,8 @@ static int tcp_write_timeout(struct sock *sk)
tcp_mtu_probing(icsk, sk);
+ } else {
+ sk_rethink_txhash(sk);
retry_until = net->ipv4.sysctl_tcp_retries2;