kvm pre-deadlock dump

[ 5664.279283] qemu-kvm used greatest stack depth: 2416 bytes left
[ 5839.916282]
[ 5839.916284] =================================
[ 5839.916738] [ INFO: inconsistent lock state ]
[ 5839.916969] 3.1.4 #2
[ 5839.917192] ---------------------------------
[ 5839.917426] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 5839.917667] qemu-kvm/8774 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 5839.917898]  (pcpu_alloc_mutex){+.+.?.}, at: [<ffffffff8110c8be>] pcpu_alloc+0x6f/0x835
[ 5839.918394] {RECLAIM_FS-ON-W} state was registered at:
[ 5839.918627]   [<ffffffff8108f85a>] mark_held_locks+0x6d/0x95
[ 5839.918869]   [<ffffffff8108fe69>] lockdep_trace_alloc+0x9f/0xc2
[ 5839.919112]   [<ffffffff8112d781>] slab_pre_alloc_hook+0x1e/0x54
[ 5839.919354]   [<ffffffff8112fcf9>] __kmalloc+0x64/0x10c
[ 5839.919588]   [<ffffffff8110bec8>] pcpu_mem_alloc+0x5e/0x67
[ 5839.919829]   [<ffffffff8110c169>] pcpu_extend_area_map+0x2b/0xd4
[ 5839.920064]   [<ffffffff8110ca0d>] pcpu_alloc+0x1be/0x835
[ 5839.920293]   [<ffffffff8110d094>] __alloc_percpu+0x10/0x12
[ 5839.920525]   [<ffffffff8113167a>] kmem_cache_open+0x2cc/0x2d6
[ 5839.920756]   [<ffffffff8113185d>] kmem_cache_create+0x1d9/0x281
[ 5839.920987]   [<ffffffff812971a5>] acpi_os_create_cache+0x1d/0x2d
[ 5839.921220]   [<ffffffff812bf742>] acpi_ut_create_caches+0x26/0xb0
[ 5839.921457]   [<ffffffff812c2106>] acpi_ut_init_globals+0xe/0x244
[ 5839.921704]   [<ffffffff81d82ca9>] acpi_initialize_subsystem+0x35/0xae
[ 5839.921945]   [<ffffffff81d819c2>] acpi_early_init+0x5c/0xf7
[ 5839.922181]   [<ffffffff81d51be9>] start_kernel+0x3ce/0x3ea
[ 5839.922420]   [<ffffffff81d512c4>] x86_64_start_reservations+0xaf/0xb3
[ 5839.922659]   [<ffffffff81d51412>] x86_64_start_kernel+0x14a/0x159
[ 5839.922897] irq event stamp: 48683649
[ 5839.923122] hardirqs last  enabled at (48683649): [<ffffffff814fd547>] __slab_alloc+0x413/0x434
[ 5839.923581] hardirqs last disabled at (48683648): [<ffffffff814fd17c>] __slab_alloc+0x48/0x434
[ 5839.924036] softirqs last  enabled at (48683630): [<ffffffff810630bf>] __do_softirq+0x200/0x25a
[ 5839.924495] softirqs last disabled at (48683625): [<ffffffff8150debc>] call_softirq+0x1c/0x30
[ 5839.924953]
[ 5839.924953] other info that might help us debug this:
[ 5839.925396]  Possible unsafe locking scenario:
[ 5839.925397]
[ 5839.925840]        CPU0
[ 5839.926063]        ----
[ 5839.926287]   lock(pcpu_alloc_mutex);
[ 5839.926533]   <Interrupt>
[ 5839.926756]     lock(pcpu_alloc_mutex);
[ 5839.926986]
[ 5839.926987]  *** DEADLOCK ***
[ 5839.926988]
[ 5839.927650] 3 locks held by qemu-kvm/8774:
[ 5839.927880]  #0:  (&vcpu->mutex){+.+.+.}, at: [<ffffffffa005d979>] vcpu_load+0x1d/0x90 [kvm]
[ 5839.928370]  #1:  (&kvm->srcu){.+.+.+}, at: [<ffffffffa00663f7>] srcu_read_lock+0x0/0x49 [kvm]
[ 5839.928848]  #2:  (&mm->mmap_sem){++++++}, at: [<ffffffffa005ee6f>] hva_to_pfn+0xbb/0x2d1 [kvm]
[ 5839.929323]
[ 5839.929323] stack backtrace:
[ 5839.929767] Pid: 8774, comm: qemu-kvm Not tainted 3.1.4 #2
[ 5839.930001] Call Trace:
[ 5839.930224]  [<ffffffff814fa906>] print_usage_bug+0x1e7/0x1f8
[ 5839.930463]  [<ffffffff8101aaa5>] ? save_stack_trace+0x2c/0x49
[ 5839.930698]  [<ffffffff8108db04>] ? print_irq_inversion_bug.part.21+0x1a0/0x1a0
[ 5839.931145]  [<ffffffff8108e232>] mark_lock+0x106/0x220
[ 5839.931378]  [<ffffffff8108e6ee>] __lock_acquire+0x3a2/0xd0c
[ 5839.931616]  [<ffffffff815047e4>] ? _raw_spin_unlock+0x29/0x3c
[ 5839.931855]  [<ffffffff8110c8be>] ? pcpu_alloc+0x6f/0x835
[ 5839.932084]  [<ffffffff8108f55b>] lock_acquire+0xf3/0x13e
[ 5839.932316]  [<ffffffff8110c8be>] ? pcpu_alloc+0x6f/0x835
[ 5839.932566]  [<ffffffff8123ed4b>] ? kzalloc_node+0x14/0x16
[ 5839.932800]  [<ffffffff8110c8be>] ? pcpu_alloc+0x6f/0x835
[ 5839.933033]  [<ffffffff815030ad>] __mutex_lock_common+0x5d/0x39a
[ 5839.933267]  [<ffffffff8110c8be>] ? pcpu_alloc+0x6f/0x835
[ 5839.933503]  [<ffffffff8108f9a3>] ? trace_hardirqs_on_caller+0x121/0x158
[ 5839.933742]  [<ffffffff814fd553>] ? __slab_alloc+0x41f/0x434
[ 5839.933975]  [<ffffffff815034f9>] mutex_lock_nested+0x40/0x45
[ 5839.934205]  [<ffffffff8110c8be>] pcpu_alloc+0x6f/0x835
[ 5839.934433]  [<ffffffff8125334d>] ? random32+0x2d/0x33
[ 5839.934672]  [<ffffffff8125f8cb>] ? should_fail+0x8d/0xeb
[ 5839.934910]  [<ffffffff8110d094>] __alloc_percpu+0x10/0x12
[ 5839.935141]  [<ffffffff8123d64c>] blkio_alloc_blkg_stats+0x1d/0x31
[ 5839.935370]  [<ffffffff8123ed87>] throtl_alloc_tg+0x3a/0xdf
[ 5839.935598]  [<ffffffff8123f79f>] blk_throtl_bio+0x154/0x39c
[ 5839.935829]  [<ffffffff810f37ad>] ? mempool_alloc_slab+0x15/0x17
[ 5839.936059]  [<ffffffff811310d1>] ? kmem_cache_alloc+0x53/0x13a
[ 5839.936297]  [<ffffffff81231c52>] generic_make_request+0x2e4/0x415
[ 5839.936534]  [<ffffffff81504dff>] ? _raw_spin_unlock_irqrestore+0x45/0x61
[ 5839.936771]  [<ffffffff81231e61>] submit_bio+0xde/0xfd
[ 5839.937009]  [<ffffffff810f9444>] ? account_page_writeback+0x13/0x15
[ 5839.937248]  [<ffffffff810f975a>] ? test_set_page_writeback+0xeb/0xfd
[ 5839.937487]  [<ffffffff8111e15d>] swap_writepage+0x94/0x9f
[ 5839.937726]  [<ffffffff811041d1>] shmem_writepage+0x192/0x1d8
[ 5839.937958]  [<ffffffff8110167b>] shrink_page_list+0x402/0x79a
[ 5839.938192]  [<ffffffff81101e1a>] shrink_inactive_list+0x22c/0x3df
[ 5839.938433]  [<ffffffff8108f85a>] ? mark_held_locks+0x6d/0x95
[ 5839.938665]  [<ffffffff811026b2>] shrink_zone+0x43f/0x582
[ 5839.938907]  [<ffffffff810839d4>] ? ktime_get_ts+0x85/0x8e
[ 5839.939146]  [<ffffffff81102b5e>] do_try_to_free_pages+0x107/0x318
[ 5839.939383]  [<ffffffff811030a6>] try_to_free_pages+0xd5/0x175
[ 5839.939615]  [<ffffffff810f9021>] __alloc_pages_nodemask+0x535/0x7eb
[ 5839.939854]  [<ffffffff8101542e>] ? sched_clock+0x15/0x19
[ 5839.940092]  [<ffffffff81127f02>] alloc_pages_vma+0xf5/0xfa
[ 5839.940326]  [<ffffffff81136bfb>] do_huge_pmd_anonymous_page+0xb3/0x274
[ 5839.940564]  [<ffffffff8110e126>] ? pmd_offset+0x19/0x3f
[ 5839.940796]  [<ffffffff811112f2>] handle_mm_fault+0xfd/0x1b8
[ 5839.941028]  [<ffffffff8111173c>] __get_user_pages+0x2fa/0x465
[ 5839.941269]  [<ffffffffa005edb2>] get_user_page_nowait+0x37/0x39 [kvm]
[ 5839.941509]  [<ffffffffa005ee8a>] hva_to_pfn+0xd6/0x2d1 [kvm]
[ 5839.941751]  [<ffffffffa005cbe7>] ? kvm_memslots+0x57/0x8c [kvm]
[ 5839.941992]  [<ffffffffa005cd82>] ? gfn_to_memslot+0x13/0x44 [kvm]
[ 5839.942237]  [<ffffffffa005f108>] __gfn_to_pfn+0x83/0x8c [kvm]
[ 5839.942484]  [<ffffffffa005f1c9>] gfn_to_pfn_async+0x1a/0x1c [kvm]
[ 5839.942736]  [<ffffffffa007799e>] try_async_pf+0x3f/0x248 [kvm]
[ 5839.942978]  [<ffffffffa005ed6f>] ? kvm_host_page_size+0x83/0x8f [kvm]
[ 5839.943229]  [<ffffffffa0079140>] tdp_page_fault+0xe8/0x1a5 [kvm]
[ 5839.943482]  [<ffffffffa0077c83>] kvm_mmu_page_fault+0x2b/0x83 [kvm]
[ 5839.943725]  [<ffffffffa00cda71>] handle_ept_violation+0xe1/0xea [kvm_intel]
[ 5839.943969]  [<ffffffffa00d2129>] vmx_handle_exit+0x5ee/0x638 [kvm_intel]
[ 5839.944244]  [<ffffffffa0066436>] ? srcu_read_lock+0x3f/0x49 [kvm]
[ 5839.944556]  [<ffffffffa00663f7>] ? init_emulate_ctxt+0x131/0x131 [kvm]
[ 5839.944818]  [<ffffffffa007153f>] kvm_arch_vcpu_ioctl_run+0xb30/0xe00 [kvm]
[ 5839.945080]  [<ffffffffa006c9ea>] ? kvm_arch_vcpu_load+0x14d/0x158 [kvm]
[ 5839.945339]  [<ffffffffa005db4f>] kvm_vcpu_ioctl+0x120/0x59c [kvm]
[ 5839.945576]  [<ffffffff81203da6>] ? file_has_perm+0xa7/0xc9
[ 5839.945826]  [<ffffffff811502a5>] do_vfs_ioctl+0x472/0x4b3
[ 5839.946067]  [<ffffffff8115033c>] sys_ioctl+0x56/0x7a
[ 5839.946305]  [<ffffffff8150bbc2>] system_call_fastpath+0x16/0x1b