With all those fixes backported we still got a kernel lockup:
Apr 21 11:55:25 kernel: [992864.965769] Pid: 0, comm: swapper/0 Tainted: P C O 3.2.0-77-generic #112hf79117v20150224b1-Ubuntu Apr 21 11:55:25 kernel: [992864.965772] Call Trace: Apr 21 11:55:25 kernel: [992864.965773] <IRQ> [<ffffffff8106845f>] warn_slowpath_common+0x7f/0xc0 Apr 21 11:55:25 kernel: [992864.965786] [<ffffffff8104f624>] ? __enqueue_entity+0x74/0x80 Apr 21 11:55:25 kernel: [992864.965790] [<ffffffff81068556>] warn_slowpath_fmt+0x46/0x50 Apr 21 11:55:25 kernel: [992864.965794] [<ffffffff81025712>] ? x86_pmu_enable+0x1f2/0x270 Apr 21 11:55:25 kernel: [992864.965800] [<ffffffff81568e0a>] dev_watchdog+0x25a/0x270 Apr 21 11:55:25 kernel: [992864.965805] [<ffffffff811133f0>] ? perf_rotate_context+0x110/0x220 Apr 21 11:55:25 kernel: [992864.965809] [<ffffffff81568bb0>] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965813] [<ffffffff81568bb0>] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965819] [<ffffffff81077466>] call_timer_fn+0x46/0x160 Apr 21 11:55:25 kernel: [992864.965823] [<ffffffff81568bb0>] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965827] [<ffffffff81078db2>] run_timer_softirq+0x132/0x2a0 Apr 21 11:55:25 kernel: [992864.965833] [<ffffffff81096675>] ? ktime_get+0x65/0xe0 Apr 21 11:55:25 kernel: [992864.965836] [<ffffffff8106fcf8>] __do_softirq+0xa8/0x210 Apr 21 11:55:25 kernel: [992864.965841] [<ffffffff8109d714>] ? tick_program_event+0x24/0x30 Apr 21 11:55:25 kernel: [992864.965845] [<ffffffff8166f06c>] call_softirq+0x1c/0x30 Apr 21 11:55:25 kernel: [992864.965851] [<ffffffff810164e5>] do_softirq+0x65/0xa0 Apr 21 11:55:25 kernel: [992864.965854] [<ffffffff810700de>] irq_exit+0x8e/0xb0 Apr 21 11:55:25 kernel: [992864.965858] [<ffffffff8166fa1e>] smp_apic_timer_interrupt+0x6e/0x99 Apr 21 11:55:25 kernel: [992864.965863] [<ffffffff8166d8de>] apic_timer_interrupt+0x6e/0x80 Apr 21 11:55:25 kernel: [992864.965865] <EOI> [<ffffffff8109c184>] ? clockevents_program_event+0x74/0x100 Apr 21 11:55:25 kernel: [992864.965873] [<ffffffff81371a5d>] ? intel_idle+0xed/0x150 Apr 21 11:55:25 kernel: [992864.965877] [<ffffffff81371a3f>] ? intel_idle+0xcf/0x150 Apr 21 11:55:25 kernel: [992864.965883] [<ffffffff8150e921>] cpuidle_idle_call+0xc1/0x290 Apr 21 11:55:25 kernel: [992864.965887] [<ffffffff8101322a>] cpu_idle+0xca/0x120 Apr 21 11:55:25 kernel: [992864.965892] [<ffffffff8162af5e>] rest_init+0x72/0x74 Apr 21 11:55:25 kernel: [992864.965897] [<ffffffff81cfbc0b>] start_kernel+0x3ba/0x3c7 Apr 21 11:55:25 kernel: [992864.965902] [<ffffffff81cfb388>] x86_64_start_reservations+0x132/0x136 Apr 21 11:55:25 kernel: [992864.965907] [<ffffffff81cfb140>] ? early_idt_handlers+0x140/0x140 Apr 21 11:55:25 kernel: [992864.965911] [<ffffffff81cfb459>] x86_64_start_kernel+0xcd/0xdc Apr 21 11:55:25 kernel: [992864.965914] ---[ end trace f20333a4474e470d ]--- Apr 21 11:55:25 kernel: [992864.965930] e1000e 0000:00:19.0: eth0: Reset adapter Apr 21 11:55:29 kernel: [992868.720990] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
It looks like network interface was restored after some time but I asked for a kernel dump and more information regarding the network topology.
With all those fixes backported we still got a kernel lockup:
Apr 21 11:55:25 kernel: [992864.965769] Pid: 0, comm: swapper/0 Tainted: P C O 3.2.0-77-generic #112hf79117v201 50224b1- Ubuntu 45f>] warn_slowpath_ common+ 0x7f/0xc0 624>] ? __enqueue_ entity+ 0x74/0x80 556>] warn_slowpath_ fmt+0x46/ 0x50 712>] ? x86_pmu_ enable+ 0x1f2/0x270 e0a>] dev_watchdog+ 0x25a/0x270 3f0>] ? perf_rotate_ context+ 0x110/0x220 bb0>] ? qdisc_reset+ 0x50/0x50 bb0>] ? qdisc_reset+ 0x50/0x50 466>] call_timer_ fn+0x46/ 0x160 bb0>] ? qdisc_reset+ 0x50/0x50 db2>] run_timer_ softirq+ 0x132/0x2a0 675>] ? ktime_get+0x65/0xe0 cf8>] __do_softirq+ 0xa8/0x210 714>] ? tick_program_ event+0x24/ 0x30 06c>] call_softirq+ 0x1c/0x30 4e5>] do_softirq+ 0x65/0xa0 0de>] irq_exit+0x8e/0xb0 a1e>] smp_apic_ timer_interrupt +0x6e/0x99 8de>] apic_timer_ interrupt+ 0x6e/0x80 184>] ? clockevents_ program_ event+0x74/ 0x100 a5d>] ? intel_idle+ 0xed/0x150 a3f>] ? intel_idle+ 0xcf/0x150 921>] cpuidle_ idle_call+ 0xc1/0x290 22a>] cpu_idle+0xca/0x120 f5e>] rest_init+0x72/0x74 c0b>] start_kernel+ 0x3ba/0x3c7 388>] x86_64_ start_reservati ons+0x132/ 0x136 140>] ? early_idt_ handlers+ 0x140/0x140 459>] x86_64_ start_kernel+ 0xcd/0xdc
Apr 21 11:55:25 kernel: [992864.965772] Call Trace:
Apr 21 11:55:25 kernel: [992864.965773] <IRQ> [<ffffffff81068
Apr 21 11:55:25 kernel: [992864.965786] [<ffffffff8104f
Apr 21 11:55:25 kernel: [992864.965790] [<ffffffff81068
Apr 21 11:55:25 kernel: [992864.965794] [<ffffffff81025
Apr 21 11:55:25 kernel: [992864.965800] [<ffffffff81568
Apr 21 11:55:25 kernel: [992864.965805] [<ffffffff81113
Apr 21 11:55:25 kernel: [992864.965809] [<ffffffff81568
Apr 21 11:55:25 kernel: [992864.965813] [<ffffffff81568
Apr 21 11:55:25 kernel: [992864.965819] [<ffffffff81077
Apr 21 11:55:25 kernel: [992864.965823] [<ffffffff81568
Apr 21 11:55:25 kernel: [992864.965827] [<ffffffff81078
Apr 21 11:55:25 kernel: [992864.965833] [<ffffffff81096
Apr 21 11:55:25 kernel: [992864.965836] [<ffffffff8106f
Apr 21 11:55:25 kernel: [992864.965841] [<ffffffff8109d
Apr 21 11:55:25 kernel: [992864.965845] [<ffffffff8166f
Apr 21 11:55:25 kernel: [992864.965851] [<ffffffff81016
Apr 21 11:55:25 kernel: [992864.965854] [<ffffffff81070
Apr 21 11:55:25 kernel: [992864.965858] [<ffffffff8166f
Apr 21 11:55:25 kernel: [992864.965863] [<ffffffff8166d
Apr 21 11:55:25 kernel: [992864.965865] <EOI> [<ffffffff8109c
Apr 21 11:55:25 kernel: [992864.965873] [<ffffffff81371
Apr 21 11:55:25 kernel: [992864.965877] [<ffffffff81371
Apr 21 11:55:25 kernel: [992864.965883] [<ffffffff8150e
Apr 21 11:55:25 kernel: [992864.965887] [<ffffffff81013
Apr 21 11:55:25 kernel: [992864.965892] [<ffffffff8162a
Apr 21 11:55:25 kernel: [992864.965897] [<ffffffff81cfb
Apr 21 11:55:25 kernel: [992864.965902] [<ffffffff81cfb
Apr 21 11:55:25 kernel: [992864.965907] [<ffffffff81cfb
Apr 21 11:55:25 kernel: [992864.965911] [<ffffffff81cfb
Apr 21 11:55:25 kernel: [992864.965914] ---[ end trace f20333a4474e470d ]---
Apr 21 11:55:25 kernel: [992864.965930] e1000e 0000:00:19.0: eth0: Reset adapter
Apr 21 11:55:29 kernel: [992868.720990] e1000e: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
It looks like network interface was restored after some time but I asked for a kernel dump and more information regarding the network topology.