On 04/15/2018 06:47 PM, Dominique Martinet wrote:
> Also, here are the per-socket stats I could find (ss -i after having
> reproduced hang):
> reno wscale:7,7 rto:7456 backoff:5 rtt:32.924/1.41 ato:40 mss:1374
> pmtu:1500 rcvmss:1248 advmss:1448 cwnd:1 ssthresh:16
> bytes_acked:32004 bytes_received:4189 segs_out:85 segs_in:54
> data_segs_out:78 data_segs_in:18 send 333.9Kbps lastsnd:3912
> lastrcv:11464 lastack:11387 pacing_rate 21.4Mbps delivery_rate
> 3.5Mbps busy:12188ms unacked:33 retrans:1/5 lost:33 rcv_rtt:37
> rcv_space:29200 rcv_ssthresh:39184 notsent:28796 minrtt:24.986
ss -temoi might give us more info
Really it looks like at some point, all incoming packets are shown by tcpdump
but do not reach the TCP socket anymore.
(segs_in: might be steady, look at the d0 counter shown by ss -temoi (dX :
drop counters, sk->sk_drops)
Are you sure you do not have some iptables/netfilter stuff ?
While running your experiment, try on the server.
perf record -a -g -e skb:kfree_skb sleep 30