KY has pushed a patch to LKML that resolves this issue: https://lkml.org/lkml/2015/11/18/690
This patch needs to be applied to the Vivid kernel and beyond. This is a critical patch, can you please take this patch as sauce for now so we can get it out as quickly as possible? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1508706 Title: Networking hangs on azure using hv_netvsc; bisected Status in linux package in Ubuntu: Triaged Bug description: Running Ubuntu instances on azure, testing basic networking between two instances. This involves configuring VXLAN between the two instances and running iperf and rsync of the kernel tree between the instances, e.g., ip link add vxlan0 type vxlan id 999 local 10.88.0.12 remote 10.88.0.11 dev eth0 ip l set vxlan0 up ip addr add 242.0.0.12/8 dev vxlan0 After some time (sometimes instantly, sometimes up to 30 minutes of activity), the networking will hang. This hang takes two forms: a complete loss of connectivity (all network, even the ssh session used to log in), or just a loss of connectivity between instances (the ssh session remains active). Sometimes for the latter case, the ssh session will then later hang. This first appeared when testing with the Ubuntu 3.19 kernel, and I subsequently bisected this to: commit effa2012d207f78cbc5a8360e62d420a8860b7e9 Author: KY Srinivasan <k...@microsoft.com> Date: Mon May 11 15:39:46 2015 -0700 hv_netvsc: Use the xmit_more skb flag to optimize signaling the host BugLink: http://bugs.launchpad.net/bugs/1454892 Based on the information given to this driver (via the xmit_more skb flag), we can defer signaling the host if more packets are on the way. This will help make the host more efficient since it can potentially process a larger batch of packets. Implement this optimization. Signed-off-by: K. Y. Srinivasan <k...@microsoft.com> Signed-off-by: David S. Miller <da...@davemloft.net> Acked-by: Tim Gardner <tim.gard...@canonical.com> Acked-by: Brad Figg <brad.f...@canonical.com> Signed-off-by: Brad Figg <brad.f...@canonical.com> I also tested the mainline kernel (net-next); it fails with the equivalent commit: commit 82fa3c776e5abba7ed6e4b4f4983d14731c37d6a Author: KY Srinivasan <k...@microsoft.com> Date: Mon May 11 15:39:46 2015 -0700 hv_netvsc: Use the xmit_more skb flag to optimize signaling the host For both kernel trees, I also tested the prior commit and it did not exhibit the failure after many hours. For ubuntu, this was commit a4aeb290bd75af5e16a6144a418291476ac6140c Author: K. Y. Srinivasan <k...@microsoft.com> Date: Wed Mar 18 12:29:29 2015 -0700 Drivers: hv: vmbus: Export the vmbus_sendpacket_pagebuffer_ctl() and for mainline it was commit 9eea92226407e7a117ef1ceef45380ebd000a0e2 Author: Alexei Starovoitov <a...@plumgrid.com> Date: Mon May 11 15:19:48 2015 -0700 pktgen: fix packet generation To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1508706/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
