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] [] warn_slowpath_common+0x7f/0xc0 Apr 21 11:55:25 kernel: [992864.965786] [] ? __enqueue_entity+0x74/0x80 Apr 21 11:55:25 kernel: [992864.965790] [] warn_slowpath_fmt+0x46/0x50 Apr 21 11:55:25 kernel: [992864.965794] [] ? x86_pmu_enable+0x1f2/0x270 Apr 21 11:55:25 kernel: [992864.965800] [] dev_watchdog+0x25a/0x270 Apr 21 11:55:25 kernel: [992864.965805] [] ? perf_rotate_context+0x110/0x220 Apr 21 11:55:25 kernel: [992864.965809] [] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965813] [] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965819] [] call_timer_fn+0x46/0x160 Apr 21 11:55:25 kernel: [992864.965823] [] ? qdisc_reset+0x50/0x50 Apr 21 11:55:25 kernel: [992864.965827] [] run_timer_softirq+0x132/0x2a0 Apr 21 11:55:25 kernel: [992864.965833] [] ? ktime_get+0x65/0xe0 Apr 21 11:55:25 kernel: [992864.965836] [] __do_softirq+0xa8/0x210 Apr 21 11:55:25 kernel: [992864.965841] [] ? tick_program_event+0x24/0x30 Apr 21 11:55:25 kernel: [992864.965845] [] call_softirq+0x1c/0x30 Apr 21 11:55:25 kernel: [992864.965851] [] do_softirq+0x65/0xa0 Apr 21 11:55:25 kernel: [992864.965854] [] irq_exit+0x8e/0xb0 Apr 21 11:55:25 kernel: [992864.965858] [] smp_apic_timer_interrupt+0x6e/0x99 Apr 21 11:55:25 kernel: [992864.965863] [] apic_timer_interrupt+0x6e/0x80 Apr 21 11:55:25 kernel: [992864.965865] [] ? clockevents_program_event+0x74/0x100 Apr 21 11:55:25 kernel: [992864.965873] [] ? intel_idle+0xed/0x150 Apr 21 11:55:25 kernel: [992864.965877] [] ? intel_idle+0xcf/0x150 Apr 21 11:55:25 kernel: [992864.965883] [] cpuidle_idle_call+0xc1/0x290 Apr 21 11:55:25 kernel: [992864.965887] [] cpu_idle+0xca/0x120 Apr 21 11:55:25 kernel: [992864.965892] [] rest_init+0x72/0x74 Apr 21 11:55:25 kernel: [992864.965897] [] start_kernel+0x3ba/0x3c7 Apr 21 11:55:25 kernel: [992864.965902] [] x86_64_start_reservations+0x132/0x136 Apr 21 11:55:25 kernel: [992864.965907] [] ? early_idt_handlers+0x140/0x140 Apr 21 11:55:25 kernel: [992864.965911] [] 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.