$ uname -a
Linux localhost.localdomain 4.15.7-300.fc27.x86_64+debug #1 SMP Wed
Feb 28 17:32:16 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux


How reproduce:
1. start virtual machine
2. open attached html page (omhed.html) in Firefox which will helps
occurred OOM.

[ 2335.903277] INFO: task CPU 0/KVM:7450 blocked for more than 120 seconds.
[ 2335.903284]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2335.903287] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2335.903291] CPU 0/KVM       D10648  7450      1 0x00000000
[ 2335.903298] Call Trace:
[ 2335.903308]  ? __schedule+0x2e9/0xbb0
[ 2335.903318]  ? __lock_page+0xad/0x180
[ 2335.903322]  schedule+0x2f/0x90
[ 2335.903327]  io_schedule+0x12/0x40
[ 2335.903331]  __lock_page+0xed/0x180
[ 2335.903338]  ? page_cache_tree_insert+0x130/0x130
[ 2335.903347]  deferred_split_scan+0x318/0x340
[ 2335.903358]  shrink_slab.part.48+0x202/0x5a0
[ 2335.903368]  ? percpu_ref_put_many+0x84/0x110
[ 2335.903378]  shrink_node+0x2f4/0x300
[ 2335.903390]  do_try_to_free_pages+0xca/0x350
[ 2335.903399]  try_to_free_pages+0x140/0x350
[ 2335.903411]  __alloc_pages_slowpath+0x43c/0x1080
[ 2335.903417]  ? __lock_acquire+0x2d4/0x1340
[ 2335.903437]  __alloc_pages_nodemask+0x3af/0x440
[ 2335.903448]  alloc_pages_vma+0x7c/0x200
[ 2335.903456]  ksm_might_need_to_copy+0x97/0x210
[ 2335.903463]  do_swap_page+0x413/0xb50
[ 2335.903474]  __handle_mm_fault+0x89e/0x1290
[ 2335.903489]  handle_mm_fault+0x14c/0x300
[ 2335.903496]  __get_user_pages+0x1b3/0x760
[ 2335.903518]  ? __gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2335.903528]  get_user_pages+0x3e/0x50
[ 2335.903542]  __gfn_to_pfn_memslot+0x133/0x480 [kvm]
[ 2335.903564]  try_async_pf+0x67/0x3b0 [kvm]
[ 2335.903587]  tdp_page_fault+0x13e/0x290 [kvm]
[ 2335.903607]  kvm_mmu_page_fault+0x59/0x130 [kvm]
[ 2335.903624]  kvm_arch_vcpu_ioctl_run+0x7d1/0x1ba0 [kvm]
[ 2335.903641]  ? kvm_arch_vcpu_load+0x75/0x250 [kvm]
[ 2335.903647]  ? handle_monitor_trap+0x10/0x10 [kvm_intel]
[ 2335.903658]  ? kvm_arch_vcpu_load+0x90/0x250 [kvm]
[ 2335.903674]  ? kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2335.903684]  kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2335.903698]  do_vfs_ioctl+0xa5/0x6e0
[ 2335.903709]  SyS_ioctl+0x74/0x80
[ 2335.903716]  do_syscall_64+0x79/0x220
[ 2335.903722]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 2335.903726] RIP: 0033:0x7fb1ceec50f7
[ 2335.903728] RSP: 002b:00007fb1bf364878 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 2335.903732] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1ceec50f7
[ 2335.903734] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000013
[ 2335.903736] RBP: 0000561b56cb3e40 R08: 0000561b56cce1f0 R09: 00000000000000ff
[ 2335.903739] R10: 0000000000000001 R11: 0000000000000246 R12: 0000561b57c8d5d6
[ 2335.903741] R13: 0000000000000000 R14: 00007fb1d8592000 R15: 0000561b57c8d540
[ 2335.903762]
               Showing all locks held in the system:
[ 2335.903773] 1 lock held by khungtaskd/67:
[ 2335.903776]  #0:  (tasklist_lock){.+.+}, at: [<00000000ae7bc74b>]
debug_show_all_locks+0x37/0x1a0
[ 2335.903853] 2 locks held by gnome-shell/1971:
[ 2335.903855]  #0:  (&mm->mmap_sem){++++}, at: [<00000000328d764a>]
__do_page_fault+0x17a/0x530
[ 2335.903867]  #1:  (&ei->i_mmap_sem){++++}, at: [<000000002b36ff5a>]
ext4_filemap_fault+0x27/0x3e
[ 2335.903930] 2 locks held by sbis3plugin/2761:
[ 2335.903932]  #0:  (&mm->mmap_sem){++++}, at: [<00000000328d764a>]
__do_page_fault+0x17a/0x530
[ 2335.903942]  #1:  (&ei->i_mmap_sem){++++}, at: [<000000002b36ff5a>]
ext4_filemap_fault+0x27/0x3e
[ 2335.904110] 2 locks held by opera-developer/5828:
[ 2335.904112]  #0:  (&mm->mmap_sem){++++}, at: [<00000000328d764a>]
__do_page_fault+0x17a/0x530
[ 2335.904122]  #1:  (&ei->i_mmap_sem){++++}, at: [<000000002b36ff5a>]
ext4_filemap_fault+0x27/0x3e
[ 2335.904167] 4 locks held by CPU 0/KVM/7450:
[ 2335.904169]  #0:  (&vcpu->mutex){+.+.}, at: [<000000000bb20b8b>]
vcpu_load+0x17/0x60 [kvm]
[ 2335.904188]  #1:  (&kvm->srcu){....}, at: [<000000007181f206>]
kvm_arch_vcpu_ioctl_run+0x73c/0x1ba0 [kvm]
[ 2335.904209]  #2:  (&mm->mmap_sem){++++}, at: [<00000000c6f7c4d3>]
__gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2335.904229]  #3:  (shrinker_rwsem){++++}, at: [<00000000af097e48>]
shrink_slab.part.48+0x5b/0x5a0

[ 2335.904248] =============================================

[ 2347.613324] oom_reaper: reaped process 8209 (file:// Content), now
anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
[ 2458.783866] INFO: task CPU 0/KVM:7450 blocked for more than 120 seconds.
[ 2458.783871]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2458.783873] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2458.783876] CPU 0/KVM       D10648  7450      1 0x00000000
[ 2458.783881] Call Trace:
[ 2458.783889]  ? __schedule+0x2e9/0xbb0
[ 2458.783895]  ? __lock_page+0xad/0x180
[ 2458.783898]  schedule+0x2f/0x90
[ 2458.783900]  io_schedule+0x12/0x40
[ 2458.783903]  __lock_page+0xed/0x180
[ 2458.783908]  ? page_cache_tree_insert+0x130/0x130
[ 2458.783913]  deferred_split_scan+0x318/0x340
[ 2458.783920]  shrink_slab.part.48+0x202/0x5a0
[ 2458.783926]  ? percpu_ref_put_many+0x84/0x110
[ 2458.783932]  shrink_node+0x2f4/0x300
[ 2458.783939]  do_try_to_free_pages+0xca/0x350
[ 2458.783944]  try_to_free_pages+0x140/0x350
[ 2458.783951]  __alloc_pages_slowpath+0x43c/0x1080
[ 2458.783954]  ? __lock_acquire+0x2d4/0x1340
[ 2458.783965]  __alloc_pages_nodemask+0x3af/0x440
[ 2458.783971]  alloc_pages_vma+0x7c/0x200
[ 2458.783975]  ksm_might_need_to_copy+0x97/0x210
[ 2458.783979]  do_swap_page+0x413/0xb50
[ 2458.783985]  __handle_mm_fault+0x89e/0x1290
[ 2458.783994]  handle_mm_fault+0x14c/0x300
[ 2458.783998]  __get_user_pages+0x1b3/0x760
[ 2458.784014]  ? __gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2458.784020]  get_user_pages+0x3e/0x50
[ 2458.784029]  __gfn_to_pfn_memslot+0x133/0x480 [kvm]
[ 2458.784043]  try_async_pf+0x67/0x3b0 [kvm]
[ 2458.784057]  tdp_page_fault+0x13e/0x290 [kvm]
[ 2458.784070]  kvm_mmu_page_fault+0x59/0x130 [kvm]
[ 2458.784080]  kvm_arch_vcpu_ioctl_run+0x7d1/0x1ba0 [kvm]
[ 2458.784092]  ? kvm_arch_vcpu_load+0x75/0x250 [kvm]
[ 2458.784096]  ? handle_monitor_trap+0x10/0x10 [kvm_intel]
[ 2458.784103]  ? kvm_arch_vcpu_load+0x90/0x250 [kvm]
[ 2458.784113]  ? kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2458.784119]  kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2458.784127]  do_vfs_ioctl+0xa5/0x6e0
[ 2458.784134]  SyS_ioctl+0x74/0x80
[ 2458.784138]  do_syscall_64+0x79/0x220
[ 2458.784142]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 2458.784144] RIP: 0033:0x7fb1ceec50f7
[ 2458.784146] RSP: 002b:00007fb1bf364878 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 2458.784148] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1ceec50f7
[ 2458.784150] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000013
[ 2458.784151] RBP: 0000561b56cb3e40 R08: 0000561b56cce1f0 R09: 00000000000000ff
[ 2458.784152] R10: 0000000000000001 R11: 0000000000000246 R12: 0000561b57c8d5d6
[ 2458.784154] R13: 0000000000000000 R14: 00007fb1d8592000 R15: 0000561b57c8d540
[ 2458.784166]
               Showing all locks held in the system:
[ 2458.784175] 1 lock held by khungtaskd/67:
[ 2458.784176]  #0:  (tasklist_lock){.+.+}, at: [<00000000ae7bc74b>]
debug_show_all_locks+0x37/0x1a0
[ 2458.784187] 2 locks held by kworker/u16:2/145:
[ 2458.784188]  #0:  ((wq_completion)"events_unbound"){+.+.}, at:
[<000000001b0d8f9e>] process_one_work+0x1da/0x6e0
[ 2458.784196]  #1:  ((work_completion)(&state->commit_work)){+.+.},
at: [<000000001b0d8f9e>] process_one_work+0x1da/0x6e0
[ 2458.784443] 4 locks held by CPU 0/KVM/7450:
[ 2458.784444]  #0:  (&vcpu->mutex){+.+.}, at: [<000000000bb20b8b>]
vcpu_load+0x17/0x60 [kvm]
[ 2458.784456]  #1:  (&kvm->srcu){....}, at: [<000000007181f206>]
kvm_arch_vcpu_ioctl_run+0x73c/0x1ba0 [kvm]
[ 2458.784468]  #2:  (&mm->mmap_sem){++++}, at: [<00000000c6f7c4d3>]
__gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2458.784479]  #3:  (shrinker_rwsem){++++}, at: [<00000000af097e48>]
shrink_slab.part.48+0x5b/0x5a0
[ 2458.784489] 2 locks held by file:// Content/8209:
[ 2458.784490]  #0:  (&type->s_umount_key#46){++++}, at:
[<000000004e26f718>] deactivate_super+0x33/0x50
[ 2458.784498]  #1:  (shrinker_rwsem){++++}, at: [<000000009cbdd6d5>]
unregister_shrinker+0x1c/0x80

[ 2458.784507] =============================================

[ 2581.664464] INFO: task CPU 0/KVM:7450 blocked for more than 120 seconds.
[ 2581.664470]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2581.664472] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2581.664474] CPU 0/KVM       D10648  7450      1 0x00000000
[ 2581.664479] Call Trace:
[ 2581.664487]  ? __schedule+0x2e9/0xbb0
[ 2581.664492]  ? __lock_page+0xad/0x180
[ 2581.664495]  schedule+0x2f/0x90
[ 2581.664498]  io_schedule+0x12/0x40
[ 2581.664500]  __lock_page+0xed/0x180
[ 2581.664505]  ? page_cache_tree_insert+0x130/0x130
[ 2581.664510]  deferred_split_scan+0x318/0x340
[ 2581.664517]  shrink_slab.part.48+0x202/0x5a0
[ 2581.664523]  ? percpu_ref_put_many+0x84/0x110
[ 2581.664529]  shrink_node+0x2f4/0x300
[ 2581.664535]  do_try_to_free_pages+0xca/0x350
[ 2581.664540]  try_to_free_pages+0x140/0x350
[ 2581.664547]  __alloc_pages_slowpath+0x43c/0x1080
[ 2581.664551]  ? __lock_acquire+0x2d4/0x1340
[ 2581.664561]  __alloc_pages_nodemask+0x3af/0x440
[ 2581.664567]  alloc_pages_vma+0x7c/0x200
[ 2581.664572]  ksm_might_need_to_copy+0x97/0x210
[ 2581.664577]  do_swap_page+0x413/0xb50
[ 2581.664582]  __handle_mm_fault+0x89e/0x1290
[ 2581.664590]  handle_mm_fault+0x14c/0x300
[ 2581.664594]  __get_user_pages+0x1b3/0x760
[ 2581.664616]  ? __gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2581.664622]  get_user_pages+0x3e/0x50
[ 2581.664631]  __gfn_to_pfn_memslot+0x133/0x480 [kvm]
[ 2581.664645]  try_async_pf+0x67/0x3b0 [kvm]
[ 2581.664659]  tdp_page_fault+0x13e/0x290 [kvm]
[ 2581.664672]  kvm_mmu_page_fault+0x59/0x130 [kvm]
[ 2581.664683]  kvm_arch_vcpu_ioctl_run+0x7d1/0x1ba0 [kvm]
[ 2581.664694]  ? kvm_arch_vcpu_load+0x75/0x250 [kvm]
[ 2581.664708]  ? handle_monitor_trap+0x10/0x10 [kvm_intel]
[ 2581.664716]  ? kvm_arch_vcpu_load+0x90/0x250 [kvm]
[ 2581.664726]  ? kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2581.664733]  kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2581.664741]  do_vfs_ioctl+0xa5/0x6e0
[ 2581.664747]  SyS_ioctl+0x74/0x80
[ 2581.664752]  do_syscall_64+0x79/0x220
[ 2581.664755]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 2581.664758] RIP: 0033:0x7fb1ceec50f7
[ 2581.664759] RSP: 002b:00007fb1bf364878 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 2581.664762] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1ceec50f7
[ 2581.664763] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000013
[ 2581.664764] RBP: 0000561b56cb3e40 R08: 0000561b56cce1f0 R09: 00000000000000ff
[ 2581.664766] R10: 0000000000000001 R11: 0000000000000246 R12: 0000561b57c8d5d6
[ 2581.664767] R13: 0000000000000000 R14: 00007fb1d8592000 R15: 0000561b57c8d540
[ 2581.664779] INFO: task file:// Content:8209 blocked for more than
120 seconds.
[ 2581.664782]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2581.664784] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2581.664786] file:// Content D11576  8209   3533 0x80000106
[ 2581.664790] Call Trace:
[ 2581.664794]  ? __schedule+0x2e9/0xbb0
[ 2581.664809]  ? rwsem_down_write_failed+0x2cc/0x4d0
[ 2581.664811]  schedule+0x2f/0x90
[ 2581.664813]  rwsem_down_write_failed+0x2d1/0x4d0
[ 2581.664822]  ? call_rwsem_down_write_failed+0x13/0x20
[ 2581.664824]  call_rwsem_down_write_failed+0x13/0x20
[ 2581.664828]  down_write+0x8a/0xb0
[ 2581.664830]  unregister_shrinker+0x1c/0x80
[ 2581.664834]  deactivate_locked_super+0x33/0x70
[ 2581.664837]  cleanup_mnt+0x3b/0x70
[ 2581.664840]  put_ipc_ns+0x37/0x90
[ 2581.664843]  free_nsproxy+0x3b/0xa0
[ 2581.664846]  do_exit+0x340/0xd70
[ 2581.664850]  ? get_signal+0x2ea/0x890
[ 2581.664854]  do_group_exit+0x47/0xc0
[ 2581.664857]  get_signal+0x2ab/0x890
[ 2581.664862]  ? page_fault+0x65/0x80
[ 2581.664866]  do_signal+0x36/0x640
[ 2581.664872]  ? handle_mm_fault+0x14c/0x300
[ 2581.664877]  ? __do_page_fault+0x28c/0x530
[ 2581.664881]  ? page_fault+0x65/0x80
[ 2581.664884]  exit_to_usermode_loop+0x73/0xb0
[ 2581.664887]  prepare_exit_to_usermode+0xb8/0xc0
[ 2581.664889]  retint_user+0x8/0x18
[ 2581.664891] RIP: 0033:0x7f9d6ed78b40
[ 2581.664892] RSP: 002b:00007ffcc14d0398 EFLAGS: 00010246
[ 2581.664895] RAX: 0000000000000000 RBX: 00007f899b54a000 RCX: 0000000000000000
[ 2581.664896] RDX: 00007ffcc14d03ec RSI: 0000000000000000 RDI: 00000000000001d8
[ 2581.664897] RBP: 00007ffcc14d03d0 R08: 00007f9d7154d0a8 R09: 00007f8a74f314f8
[ 2581.664898] R10: 00007f899b548800 R11: 00000000fffffff0 R12: 00007ffcc14d03ec
[ 2581.664900] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 2581.664909]
               Showing all locks held in the system:
[ 2581.664918] 1 lock held by khungtaskd/67:
[ 2581.664919]  #0:  (tasklist_lock){.+.+}, at: [<00000000ae7bc74b>]
debug_show_all_locks+0x37/0x1a0
[ 2581.665075] 2 locks held by opera-developer/4236:
[ 2581.665076]  #0:  (&type->s_umount_key#4/1){+.+.}, at:
[<00000000c6bc71b9>] sget_userns+0x155/0x500
[ 2581.665094]  #1:  (shrinker_rwsem){++++}, at: [<000000006b6cfc5f>]
register_shrinker+0x4a/0xb0
[ 2581.665242] 4 locks held by CPU 0/KVM/7450:
[ 2581.665244]  #0:  (&vcpu->mutex){+.+.}, at: [<000000000bb20b8b>]
vcpu_load+0x17/0x60 [kvm]
[ 2581.665271]  #1:  (&kvm->srcu){....}, at: [<000000007181f206>]
kvm_arch_vcpu_ioctl_run+0x73c/0x1ba0 [kvm]
[ 2581.665290]  #2:  (&mm->mmap_sem){++++}, at: [<00000000c6f7c4d3>]
__gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2581.665306]  #3:  (shrinker_rwsem){++++}, at: [<00000000af097e48>]
shrink_slab.part.48+0x5b/0x5a0
[ 2581.665318] 2 locks held by file:// Content/8209:
[ 2581.665319]  #0:  (&type->s_umount_key#46){++++}, at:
[<000000004e26f718>] deactivate_super+0x33/0x50
[ 2581.665330]  #1:  (shrinker_rwsem){++++}, at: [<000000009cbdd6d5>]
unregister_shrinker+0x1c/0x80

[ 2581.665342] =============================================

[ 2704.545628] INFO: task opera-developer:4236 blocked for more than
120 seconds.
[ 2704.545633]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2704.545635] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2704.545638] opera-developer D12136  4236   4234 0x00000000
[ 2704.545643] Call Trace:
[ 2704.545651]  ? __schedule+0x2e9/0xbb0
[ 2704.545655]  ? rwsem_down_write_failed+0x2cc/0x4d0
[ 2704.545658]  schedule+0x2f/0x90
[ 2704.545660]  rwsem_down_write_failed+0x2d1/0x4d0
[ 2704.545669]  ? call_rwsem_down_write_failed+0x13/0x20
[ 2704.545671]  call_rwsem_down_write_failed+0x13/0x20
[ 2704.545675]  down_write+0x8a/0xb0
[ 2704.545679]  register_shrinker+0x4a/0xb0
[ 2704.545684]  sget_userns+0x46e/0x500
[ 2704.545686]  ? set_anon_super+0x10/0x10
[ 2704.545689]  ? proc_get_inode+0x140/0x140
[ 2704.545693]  mount_ns+0x5b/0x100
[ 2704.545697]  mount_fs+0x35/0x150
[ 2704.545702]  vfs_kern_mount.part.25+0x54/0x150
[ 2704.545706]  kern_mount_data+0x21/0x40
[ 2704.545708]  pid_ns_prepare_proc+0x18/0x30
[ 2704.545711]  alloc_pid+0x244/0x260
[ 2704.545716]  copy_process.part.30+0x118b/0x1e70
[ 2704.545727]  _do_fork+0xe7/0x700
[ 2704.545731]  ? up_read+0x1c/0x40
[ 2704.545734]  ? __do_page_fault+0x2af/0x530
[ 2704.545738]  ? trace_hardirqs_on_caller+0xed/0x180
[ 2704.545743]  do_syscall_64+0x79/0x220
[ 2704.545747]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 2704.545749] RIP: 0033:0x7f8c6fc7c161
[ 2704.545751] RSP: 002b:00007ffd99692b08 EFLAGS: 00000202 ORIG_RAX:
0000000000000038
[ 2704.545753] RAX: ffffffffffffffda RBX: 0000000020000011 RCX: 00007f8c6fc7c161
[ 2704.545755] RDX: 0000000000000000 RSI: 00007ffd99696b10 RDI: 0000000020000011
[ 2704.545756] RBP: 00007ffd99696b30 R08: 0000000000000000 R09: 0000000000000000
[ 2704.545757] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd9969b8b0
[ 2704.545759] R13: 00007ffd996990a8 R14: 0000000000000000 R15: 0000000000000000
[ 2704.545876] INFO: task CPU 0/KVM:7450 blocked for more than 120 seconds.
[ 2704.545879]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2704.545880] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2704.545882] CPU 0/KVM       D10648  7450      1 0x00000004
[ 2704.545887] Call Trace:
[ 2704.545891]  ? __schedule+0x2e9/0xbb0
[ 2704.545897]  ? __lock_page+0xad/0x180
[ 2704.545899]  schedule+0x2f/0x90
[ 2704.545902]  io_schedule+0x12/0x40
[ 2704.545905]  __lock_page+0xed/0x180
[ 2704.545910]  ? page_cache_tree_insert+0x130/0x130
[ 2704.545915]  deferred_split_scan+0x318/0x340
[ 2704.545921]  shrink_slab.part.48+0x202/0x5a0
[ 2704.545927]  ? percpu_ref_put_many+0x84/0x110
[ 2704.545932]  shrink_node+0x2f4/0x300
[ 2704.545939]  do_try_to_free_pages+0xca/0x350
[ 2704.545944]  try_to_free_pages+0x140/0x350
[ 2704.545951]  __alloc_pages_slowpath+0x43c/0x1080
[ 2704.545954]  ? __lock_acquire+0x2d4/0x1340
[ 2704.545964]  __alloc_pages_nodemask+0x3af/0x440
[ 2704.545971]  alloc_pages_vma+0x7c/0x200
[ 2704.545975]  ksm_might_need_to_copy+0x97/0x210
[ 2704.545979]  do_swap_page+0x413/0xb50
[ 2704.545985]  __handle_mm_fault+0x89e/0x1290
[ 2704.545993]  handle_mm_fault+0x14c/0x300
[ 2704.545997]  __get_user_pages+0x1b3/0x760
[ 2704.546013]  ? __gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2704.546019]  get_user_pages+0x3e/0x50
[ 2704.546027]  __gfn_to_pfn_memslot+0x133/0x480 [kvm]
[ 2704.546041]  try_async_pf+0x67/0x3b0 [kvm]
[ 2704.546055]  tdp_page_fault+0x13e/0x290 [kvm]
[ 2704.546069]  kvm_mmu_page_fault+0x59/0x130 [kvm]
[ 2704.546080]  kvm_arch_vcpu_ioctl_run+0x7d1/0x1ba0 [kvm]
[ 2704.546091]  ? kvm_arch_vcpu_load+0x75/0x250 [kvm]
[ 2704.546098]  ? handle_monitor_trap+0x10/0x10 [kvm_intel]
[ 2704.546110]  ? kvm_arch_vcpu_load+0x90/0x250 [kvm]
[ 2704.546125]  ? kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2704.546145]  kvm_vcpu_ioctl+0x284/0x6a0 [kvm]
[ 2704.546157]  do_vfs_ioctl+0xa5/0x6e0
[ 2704.546177]  SyS_ioctl+0x74/0x80
[ 2704.546183]  do_syscall_64+0x79/0x220
[ 2704.546188]  entry_SYSCALL_64_after_hwframe+0x42/0xb7
[ 2704.546190] RIP: 0033:0x7fb1ceec50f7
[ 2704.546192] RSP: 002b:00007fb1bf364878 EFLAGS: 00000246 ORIG_RAX:
0000000000000010
[ 2704.546196] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1ceec50f7
[ 2704.546198] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000013
[ 2704.546200] RBP: 0000561b56cb3e40 R08: 0000561b56cce1f0 R09: 00000000000000ff
[ 2704.546202] R10: 0000000000000001 R11: 0000000000000246 R12: 0000561b57c8d5d6
[ 2704.546204] R13: 0000000000000000 R14: 00007fb1d8592000 R15: 0000561b57c8d540
[ 2704.546220] INFO: task file:// Content:8209 blocked for more than
120 seconds.
[ 2704.546224]       Not tainted 4.15.7-300.fc27.x86_64+debug #1
[ 2704.546226] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[ 2704.546229] file:// Content D11576  8209   3533 0x80000106
[ 2704.546234] Call Trace:
[ 2704.546240]  ? __schedule+0x2e9/0xbb0
[ 2704.546245]  ? rwsem_down_write_failed+0x2cc/0x4d0
[ 2704.546249]  schedule+0x2f/0x90
[ 2704.546252]  rwsem_down_write_failed+0x2d1/0x4d0
[ 2704.546265]  ? call_rwsem_down_write_failed+0x13/0x20
[ 2704.546278]  call_rwsem_down_write_failed+0x13/0x20
[ 2704.546284]  down_write+0x8a/0xb0
[ 2704.546289]  unregister_shrinker+0x1c/0x80
[ 2704.546294]  deactivate_locked_super+0x33/0x70
[ 2704.546297]  cleanup_mnt+0x3b/0x70
[ 2704.546310]  put_ipc_ns+0x37/0x90
[ 2704.546313]  free_nsproxy+0x3b/0xa0
[ 2704.546317]  do_exit+0x340/0xd70
[ 2704.546321]  ? get_signal+0x2ea/0x890
[ 2704.546335]  do_group_exit+0x47/0xc0
[ 2704.546339]  get_signal+0x2ab/0x890
[ 2704.546343]  ? page_fault+0x65/0x80
[ 2704.546347]  do_signal+0x36/0x640
[ 2704.546354]  ? handle_mm_fault+0x14c/0x300
[ 2704.546358]  ? __do_page_fault+0x28c/0x530
[ 2704.546363]  ? page_fault+0x65/0x80
[ 2704.546368]  exit_to_usermode_loop+0x73/0xb0
[ 2704.546372]  prepare_exit_to_usermode+0xb8/0xc0
[ 2704.546377]  retint_user+0x8/0x18
[ 2704.546380] RIP: 0033:0x7f9d6ed78b40
[ 2704.546382] RSP: 002b:00007ffcc14d0398 EFLAGS: 00010246
[ 2704.546386] RAX: 0000000000000000 RBX: 00007f899b54a000 RCX: 0000000000000000
[ 2704.546388] RDX: 00007ffcc14d03ec RSI: 0000000000000000 RDI: 00000000000001d8
[ 2704.546389] RBP: 00007ffcc14d03d0 R08: 00007f9d7154d0a8 R09: 00007f8a74f314f8
[ 2704.546391] R10: 00007f899b548800 R11: 00000000fffffff0 R12: 00007ffcc14d03ec
[ 2704.546393] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 2704.546419]
               Showing all locks held in the system:
[ 2704.546439] 1 lock held by khungtaskd/67:
[ 2704.546441]  #0:  (tasklist_lock){.+.+}, at: [<00000000ae7bc74b>]
debug_show_all_locks+0x37/0x1a0
[ 2704.546520] 2 locks held by kworker/u16:2/145:
[ 2704.546522]  #0:  ((wq_completion)"events_unbound"){+.+.}, at:
[<000000001b0d8f9e>] process_one_work+0x1da/0x6e0
[ 2704.546530]  #1:  ((work_completion)(&state->commit_work)){+.+.},
at: [<000000001b0d8f9e>] process_one_work+0x1da/0x6e0
[ 2704.546716] 2 locks held by opera-developer/4236:
[ 2704.546718]  #0:  (&type->s_umount_key#4/1){+.+.}, at:
[<00000000c6bc71b9>] sget_userns+0x155/0x500
[ 2704.546731]  #1:  (shrinker_rwsem){++++}, at: [<000000006b6cfc5f>]
register_shrinker+0x4a/0xb0
[ 2704.546886] 4 locks held by CPU 0/KVM/7450:
[ 2704.546887]  #0:  (&vcpu->mutex){+.+.}, at: [<000000000bb20b8b>]
vcpu_load+0x17/0x60 [kvm]
[ 2704.546899]  #1:  (&kvm->srcu){....}, at: [<000000007181f206>]
kvm_arch_vcpu_ioctl_run+0x73c/0x1ba0 [kvm]
[ 2704.546915]  #2:  (&mm->mmap_sem){++++}, at: [<00000000c6f7c4d3>]
__gfn_to_pfn_memslot+0x110/0x480 [kvm]
[ 2704.546943]  #3:  (shrinker_rwsem){++++}, at: [<00000000af097e48>]
shrink_slab.part.48+0x5b/0x5a0
[ 2704.546957] 2 locks held by file:// Content/8209:
[ 2704.546958]  #0:  (&type->s_umount_key#46){++++}, at:
[<000000004e26f718>] deactivate_super+0x33/0x50
[ 2704.546991]  #1:  (shrinker_rwsem){++++}, at: [<000000009cbdd6d5>]
unregister_shrinker+0x1c/0x80

[ 2704.547001] =============================================


--
Best Regards,
Mike Gavrilov.