On 2016/4/14 0:17, Eric Dumazet wrote: > On Wed, 2016-04-13 at 19:28 +0800, Ding Tianhong wrote: >> Hi everyone: >> >> I have met this problem when I try to test udp6 for nfs connection, my >> environment is: >> >> Server: >> kernel: 4.1.15 >> IP:xxxx::36/64 >> MTU:1500 >> Setting: /etc/exports:/home/nfs *(rw,sync,no_subtree_check,no_root_squash) >> >> Client: >> kernel: 4.1.18 >> IP:xxxx::90/64 >> MTU:1500 >> command: mount -t nfs -o vers=3,proto=udp6,rsize=4096,wsize=4096 >> [xxxx::36]:/home/nfs /home/tmp >> >> I check the nfs parameter configuration, it looks fine and could work well >> for proto=tcp6. >> >> Then I have mount correctly and try to run the command "ls", it hang. >> >> When I use the rsize=1024 and wsize=1024 to mount, the problem disappeared, >> so I guess it is the problem for GSO or GRO for UDP。 >> >> Then I try to debug the problem, first I tcpdump the package from cline to >> server, and found that >> the client have send readdirplus message to server correctly, and then the >> Server send a 4k package >> to client(the big package will frag to 4 package by GSO), till now it looks >> fine, and the Client Nic could >> receive the 4 skb then send to upper stack to ipv6 and udp, I found the >> incoming 4 package has been merged >> to one and send to upper stack just like sunrpc, but I try to open the >> rpc_debug, it looks that the rpc could >> not receive message. >> >> >> I built a simple demo to test the udp stack, use the client socket to send >> big package to server socket, it work well, >> so I think the udp is fine, maybe the bug is in sunrpc. >> >> The test is very simple, does any body met the same problem like me, thanks >> for any suggestion. >> >> Ding > > Have you tried to disable UFO ? > > ethtool -K eth... ufo off > > Hi Eric:
Already disabled, my nic don't support UFO. Thanks. Ding > > . >
