On Thu, 2017-02-02 at 13:34 +0100, Markus Trippelsdorf wrote:
> On 2017.02.02 at 04:32 -0800, Eric Dumazet wrote:
> > On Thu, 2017-02-02 at 12:52 +0100, Markus Trippelsdorf wrote:
> > > Hi,
> > >
> > > from time to time I see the following warning in my kernel log:
> > >
> > > TCP: eth0: Driver has suspect GRO implementation, TCP performance may be
> > > compromised.
> > >
> > > This happens although I run "/usr/sbin/ethtool -K eth0 gro off" in my
> > > local boot script.
> > > What is the warning trying to tell me?
> > >
> >
> > Please report
> >
> > ethtool -i eth0
>
> driver: ATL1E
> version: 1.0.0.7-NAPI
> firmware-version: L1e
> expansion-rom-version:
> bus-info: 0000:02:00.0
> supports-statistics: no
> supports-test: no
> supports-eeprom-access: no
> supports-register-dump: yes
> supports-priv-flags: no
>
Note that this driver does not implement GRO yet.
Hard to believe there is such push back on GRO in 2017.
Anyway, I suspect the test is simply buggy ;)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index
41dcbd568cbe2403f2a9e659669afe462a42e228..5394a39fcce964a7fe7075b1531a8a1e05550a54
100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -164,7 +164,7 @@ static void tcp_measure_rcv_mss(struct sock *sk, const
struct sk_buff *skb)
if (len >= icsk->icsk_ack.rcv_mss) {
icsk->icsk_ack.rcv_mss = min_t(unsigned int, len,
tcp_sk(sk)->advmss);
- if (unlikely(icsk->icsk_ack.rcv_mss != len))
+ if (unlikely(icsk->icsk_ack.rcv_mss != len && skb_is_gso(skb)))
tcp_gro_dev_warn(sk, skb);
} else {
/* Otherwise, we make more careful check taking into account,
