Hi All, I am using ubuntu 14.04.5 with 3.13.0-85-generic kernel in both guests and hosts. Virtual machines are connected using OVS and inside the vm i use vlan and bridge Host: ensp1>br0(ovs bridge)>tap Guest: eth0>eth0.100>br0(linux bridge)>ipaddress Frequently i am seeing non responsive vm with following call trace. BUG: soft lockup - CPU#12 stuck for 24s! [cron:13414] [2723870.261042] Modules linked in: ip6table_filter ip6_tables xt_comment xt_multiport iptable_filter xt_CHECKSUM xt_tcpudp iptable_mangle ip_tables x_tables ip_vs_rr ip_vs openvswitch(OX) gre vxlan ip_tunnel libcrc32c bridge 8021q garp stp mrp llc ttm drm_kms_helper kvm_intel drm kvm syscopyarea sysfillrect nf_conntrack_proto_gre sysimgblt nf_conntrack_ipv6 i2c_piix4 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 mac_hid serio_raw nf_conntrack raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 raid0 psmouse multipath floppy linear pata_acpi dm_multipath scsi_dh [2723870.261111] CPU: 12 PID: 13414 Comm: cron Tainted: G OX 3.13.0-85-generic #129-Ubuntu [2723870.261132] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [2723870.261138] task: ffff880c67d50000 ti: ffff880c5f2f6000 task.ti: ffff880c5f2f6000 [2723870.261140] RIP: 0010:[<ffffffff8109a117>] [<ffffffff8109a117>] finish_task_switch+0x57/0x160 [2723870.261311] RSP: 0018:ffff880c5f2f7f08 EFLAGS: 00000212 [2723870.261314] RAX: ffff880fe8a53000 RBX: ffff880b9fcf1800 RCX: 00000000c0000100 [2723870.261315] RDX: ffff880c5f2f7fd8 RSI: ffff880c67d50000 RDI: ffff88103fd93180 [2723870.261317] RBP: ffff880c5f2f7f28 R08: ffff880c5f2f6000 R09: 0000000000000000 [2723870.261319] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000013180 [2723870.261321] R13: ffff880c5f2f7fd8 R14: ffff880b9fcf1800 R15: 0000000000000046 [2723870.261325] FS: 00007ff6082f9840(0000) GS:ffff88103fd80000(0000) knlGS:0000000000000000 [2723870.261327] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [2723870.261329] CR2: 00007fb992ccb55b CR3: 0000000d40f57000 CR4: 00000000000006e0 [2723870.261345] Stack: [2723870.261348] ffff88103fd93180 ffff88103fd93180 ffff880fe3fed080 000000000000000c [2723870.261353] ffff880c5f2f7f48 ffffffff8109bbf7 ffff880fe2956200 ffff88103fd93180 [2723870.261357] ffff880c67d50000 ffffffff8173c29f 0000000000000000 0000000000000000 [2723870.261362] Call Trace: [2723870.261374] [<ffffffff8109bbf7>] schedule_tail+0x27/0xb0 [2723870.261395] [<ffffffff8173c29f>] ret_from_fork+0xf/0x90 [2723870.261397] Code: 1f 44 00 00 65 48 8b 34 25 40 b8 00 00 0f 1f 44 00 00 41 c7 44 24 28 00 00 00 00 0f 1f 44 00 00 66 83 03 02 fb 66 0f 1f 44 00 00 <65> 48 8b 04 25 40 b8 00 00 48 8b 98 18 02 00 00 48 85 db 74 1d PID in above call trace keeps on changing with cron,rsyslogd and other process Disabling GSO/TSO fixed my issues.I have seen many articles suggesting to disable GSO/TSO permanently which was written 2 years back.Is this a virt-io issue or the underlying bridge issue. Thanks for your help
