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Subject: Re: help on iproute2 hangs
To: William Tu <u9012063@gmail.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        chrism@mellanox.com
References: <CALDO+SaXQtxLkdsWM=5StJzTbnUEKBuRT+9nJRgziY9ZA3CBEg@mail.gmail.com>
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From: David Ahern <dsahern@gmail.com>
Message-ID: <8cf3efa4-6589-7347-dbde-d65ca8854bb7@gmail.com>
Date: Thu, 1 Mar 2018 14:38:16 -0700
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On 3/1/18 11:51 AM, William Tu wrote:
> root@osb:~/iproute2# ps aux | grep ip
> root       3652  0.0  0.0  11532   884 pts/24   S+   10:43   0:00 ip
> link add p0 type veth peer name ovs-p0
> 
> root@osb:~/iproute2# cat /proc/3652/stack
> [<0>] __skb_wait_for_more_packets+0x103/0x160
> [<0>] __skb_recv_datagram+0x69/0xc0
> [<0>] skb_recv_datagram+0x3f/0x60
> [<0>] netlink_recvmsg+0x59/0x420
> [<0>] ___sys_recvmsg+0xee/0x230
> [<0>] __sys_recvmsg+0x4e/0x90
> [<0>] entry_SYSCALL_64_fastpath+0x24/0x87
> [<0>] 0xffffffffffffffff
> 
> if I run strace on "ip link add p0 type veth peer name ovs-p0"
> open("/usr/lib/ip/link_veth.so", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No
> such file or directory)
> sendmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0,
> groups=00000000},
> msg_iov(1)=[{"X\0\0\0\20\0\5\6\315J\230Z\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"...,
> 88}], msg_controllen=0, msg_flags=0}, 0) = 88
> recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0,
> groups=00000000}, msg_iov(1)=[{NULL, 0}], msg_controllen=0,
> msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 36
> recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0,
> groups=00000000},
> msg_iov(1)=[{"$\0\0\0\2\0\0\1\315J\230Z1\24\0\0\0\0\0\0X\0\0\0\20\0\5\6\315J\230Z"...,
> 36}], msg_controllen=0, msg_flags=0}, 0) = 36
> 
> Thanks a lot
> William
> 

Can you send me the kernel config you use. I'll drop back to 4.15.0 and
try with that.