On Tue, Oct 30, 2018 at 10:50 AM Eric Dumazet [off-list ref] wrote:

On 10/30/2018 10:32 AM, Cong Wang wrote:

quoted

Unlike Pawel's case, we don't use vlan at all, maybe this is why we see
it much less frequently than Pawel.

Also, it is probably not specific to mlx5, as there is another report which
is probably a non-mlx5 driver.

Not sure if you provided a stack trace ?

I said it is the same with Pawel's. Here it is anyway:

[ 3731.075989] eth0: hw csum failure
[ 3731.079316] CPU: 15 PID: 0 Comm: swapper/15 Not tainted 4.14.74.x86_64 #1
[ 3731.086703] Hardware name: Wiwynn F4WW/Y 300-0284/F4WW MAIN BOARD,
BIOS F4WWP02 10/19/2018
[ 3731.094961] Call Trace:
[ 3731.097408]  <IRQ>
[ 3731.099432]  dump_stack+0x46/0x59
[ 3731.102751]  __skb_checksum_complete+0xb8/0xd0
[ 3731.107194]  tcp_v4_rcv+0x116/0xa30
[ 3731.110688]  ip_local_deliver_finish+0x5d/0x1f0
[ 3731.115218]  ip_local_deliver+0x6b/0xe0
[ 3731.119056]  ? ip_rcv_finish+0x400/0x400
[ 3731.122973]  ip_rcv+0x287/0x360
[ 3731.126112]  ? inet_del_offload+0x40/0x40
[ 3731.130124]  __netif_receive_skb_core+0x404/0xc10
[ 3731.134831]  ? netif_receive_skb_internal+0x34/0xd0
[ 3731.139709]  netif_receive_skb_internal+0x34/0xd0
[ 3731.144415]  napi_gro_receive+0xb8/0xe0
[ 3731.148271]  mlx5e_handle_rx_cqe_mpwrq+0x4e3/0x7f0 [mlx5_core]
[ 3731.154099]  ? enqueue_entity+0x103/0x7f0
[ 3731.158114]  mlx5e_poll_rx_cq+0xba/0x850 [mlx5_core]
[ 3731.163080]  mlx5e_napi_poll+0x91/0x290 [mlx5_core]
[ 3731.167955]  net_rx_action+0x14a/0x3e0
[ 3731.171707]  ? credit_entropy_bits+0x23d/0x260
[ 3731.176153]  __do_softirq+0xe2/0x2c3
[ 3731.179734]  irq_exit+0xbc/0xd0
[ 3731.182878]  do_IRQ+0x89/0xd0
[ 3731.185851]  common_interrupt+0x7a/0x7a
[ 3731.189690]  </IRQ>
[ 3731.191799] RIP: 0010:cpuidle_enter_state+0xa6/0x2d0
[ 3731.196761] RSP: 0018:ffffbb950c6f7eb0 EFLAGS: 00000246 ORIG_RAX:
ffffffffffffff60
[ 3731.204328] RAX: ffff9fe25fbe14c0 RBX: 00000364b57553af RCX: 000000000000001f
[ 3731.211459] RDX: 20c49ba5e353f7cf RSI: ffff68294248f469 RDI: 0000000000000000
[ 3731.218583] RBP: ffffdb7d003c3300 R08: 000000000000c3be R09: 0000000000008612
[ 3731.225709] R10: ffffbb950c6f7e98 R11: 000000000000c3be R12: 0000000000000003
[ 3731.232841] R13: ffffffff912c9d18 R14: 0000000000000000 R15: 00000364b396207a
[ 3731.239968]  do_idle+0x166/0x1a0
[ 3731.243199]  cpu_startup_entry+0x6f/0x80
[ 3731.247128]  start_secondary+0x19c/0x1f0
[ 3731.251052]  secondary_startup_64+0xa5/0xb0

Have you tried IPv6 frags maybe ?

We have no IPv6 traffic. I asked people to try to generate IPv4 fragment
traffic to see if it would be more reproducible, no progress yet.