WARNING: at drivers/pci/intel-iommu.c:2775 intel_unmap_page+0x15f/0x180()

Issue

• /var/log/messages had following traces

Sep 10 15:20:56 hostname1 kernel: WARNING: at drivers/pci/intel-iommu.c:2775 intel_unmap_page+0x15f/0x180() (Not tainted)
Sep 10 15:20:56 hostname1 kernel: Hardware name: ProLiant DL380p Gen8
Sep 10 15:20:56 hostname1 kernel: Driver unmaps unmatched page at PFN 0
Sep 10 15:20:56 hostname1 kernel: Modules linked in: bonding 8021q garp stp llc ipv6 vhost_net macvtap macvlan tun kvm_intel kvm uinput power_meter hpilo hpwdt igb(U) sg microcode tg3 serio_raw iTCO_wdt iTCO_v
endor_support ioatdma dca shpchp ext4 mbcache jbd2 sd_mod crc_t10dif hpsa qla2xxx scsi_transport_fc scsi_tgt pata_acpi ata_generic ata_piix dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan]
Sep 10 15:20:56 hostname1 kernel: Pid: 0, comm: swapper Not tainted 2.6.32-279.el6.x86_64 #1
Sep 10 15:20:56 hostname1 kernel: Call Trace:
Sep 10 15:20:56 hostname1 kernel: <IRQ>  [<ffffffff8106b747>] ? warn_slowpath_common+0x87/0xc0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8106b836>] ? warn_slowpath_fmt+0x46/0x50
Sep 10 15:20:56 hostname1 kernel: [<ffffffff812a835b>] ? find_iova+0x5b/0xa0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff812ac64f>] ? intel_unmap_page+0x15f/0x180
Sep 10 15:20:56 hostname1 kernel: [<ffffffffa01f7fa7>] ? igb_poll+0x137/0x1210 [igb]
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8101c954>] ? x86_pmu_enable+0x114/0x280
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8110841b>] ? perf_pmu_enable+0x2b/0x40
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8110dc18>] ? perf_event_task_tick+0xa8/0x2f0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81057fac>] ? scheduler_tick+0xcc/0x260
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8143f193>] ? net_rx_action+0x103/0x2f0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81073ec1>] ? __do_softirq+0xc1/0x1e0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff810db800>] ? handle_IRQ_event+0x60/0x170
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81073f1f>] ? __do_softirq+0x11f/0x1e0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8100c24c>] ? call_softirq+0x1c/0x30
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8100de85>] ? do_softirq+0x65/0xa0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81073ca5>] ? irq_exit+0x85/0x90
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81505af5>] ? do_IRQ+0x75/0xf0
Sep 10 15:20:56 hostname1 kernel: [<ffffffff8100ba53>] ? ret_from_intr+0x0/0x11
Sep 10 15:20:56 hostname1 kernel: <EOI>  [<ffffffff812cd8ce>] ? intel_idle+0xde/0x170
Sep 10 15:20:56 hostname1 kernel: [<ffffffff812cd8b1>] ? intel_idle+0xc1/0x170
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81407627>] ? cpuidle_idle_call+0xa7/0x140
Sep 10 15:20:56 hostname1 kernel: [<ffffffff81009e06>] ? cpu_idle+0xb6/0x110
Sep 10 15:20:56 hostname1 kernel: [<ffffffff814f6cdf>] ? start_secondary+0x22a/0x26d