| Message ID | alpine.DEB.2.00.1010141450290.26447@wel-95.cs.helsinki.fi |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi> Date: Thu, 14 Oct 2010 14:52:09 +0300 (EEST) > As CWR is stronger than CA_Disorder state, we can miscount > SACK/Reno failure into other timeouts. Not a bad problem as > it can happen only due to ECN, FRTO detecting spurious RTO > or xmit error which are the only callers of tcp_enter_cwr. > And even then losses and RTO must still follow thereafter > to actually end up into the relevant code paths. > > Compile tested. > > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Also applied to net-next-2.6, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 74c54b3..16e591e 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -365,18 +365,19 @@ void tcp_retransmit_timer(struct sock *sk) if (icsk->icsk_retransmits == 0) { int mib_idx; - if (icsk->icsk_ca_state == TCP_CA_Disorder) { - if (tcp_is_sack(tp)) - mib_idx = LINUX_MIB_TCPSACKFAILURES; - else - mib_idx = LINUX_MIB_TCPRENOFAILURES; - } else if (icsk->icsk_ca_state == TCP_CA_Recovery) { + if (icsk->icsk_ca_state == TCP_CA_Recovery) { if (tcp_is_sack(tp)) mib_idx = LINUX_MIB_TCPSACKRECOVERYFAIL; else mib_idx = LINUX_MIB_TCPRENORECOVERYFAIL; } else if (icsk->icsk_ca_state == TCP_CA_Loss) { mib_idx = LINUX_MIB_TCPLOSSFAILURES; + } else if ((icsk->icsk_ca_state == TCP_CA_Disorder) || + tp->sacked_out) { + if (tcp_is_sack(tp)) + mib_idx = LINUX_MIB_TCPSACKFAILURES; + else + mib_idx = LINUX_MIB_TCPRENOFAILURES; } else { mib_idx = LINUX_MIB_TCPTIMEOUTS; }
As CWR is stronger than CA_Disorder state, we can miscount SACK/Reno failure into other timeouts. Not a bad problem as it can happen only due to ECN, FRTO detecting spurious RTO or xmit error which are the only callers of tcp_enter_cwr. And even then losses and RTO must still follow thereafter to actually end up into the relevant code paths. Compile tested. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> --- net/ipv4/tcp_timer.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-)