Issue

• We have configured vhostmd monitoring daemon for SAP using steps in Solution 41566, but the vm-dump-metrics process is hanging with following call traces:

  INFO: task vm-dump-metrics:21050 blocked for more than 120 seconds.
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  vm-dump-metrics D ffff8801878246a0     0 21050  21010 0x00000080
  ffff880054167b10 0000000000000082 ffff8800a0830000 ffff880054167fd8
  ffff880054167fd8 ffff880054167fd8 ffff8800a0830000 ffff880187824698
  ffff88018782469c ffff8800a0830000 00000000ffffffff ffff8801878246a0
  Call Trace:
  [<ffffffff8168c969>] schedule_preempt_disabled+0x29/0x70
  [<ffffffff8168a5c5>] __mutex_lock_slowpath+0xc5/0x1c0
  [<ffffffff81689a2f>] mutex_lock+0x1f/0x2f
  [<ffffffff8123ae26>] __blkdev_get+0x76/0x4e0
  [<ffffffff8123b465>] blkdev_get+0x1d5/0x360
  [<ffffffff8123b69b>] blkdev_open+0x5b/0x80
  [<ffffffff811fbf07>] do_dentry_open+0x1a7/0x2e0
  [<ffffffff812a8a1c>] ? security_inode_permission+0x1c/0x30
  [<ffffffff8123b640>] ? blkdev_get_by_dev+0x50/0x50
  [<ffffffff811fc0df>] vfs_open+0x5f/0xe0
  [<ffffffff81209aa8>] ? may_open+0x68/0x110
  [<ffffffff8120cc4d>] do_last+0x1ed/0x12a0
  [<ffffffff811de446>] ? kmem_cache_alloc_trace+0x1d6/0x200
  [<ffffffff8120ddc2>] path_openat+0xc2/0x490
  [<ffffffff811b0f11>] ? handle_mm_fault+0x6b1/0xfe0
  [<ffffffff810f5080>] ? futex_wake+0x80/0x160
  [<ffffffff8120ff3b>] do_filp_open+0x4b/0xb0
  [<ffffffff8121cbb7>] ? __alloc_fd+0xa7/0x130
  [<ffffffff811fd443>] do_sys_open+0xf3/0x1f0
  [<ffffffff811fd55e>] SyS_open+0x1e/0x20
  [<ffffffff816967c9>] system_call_fastpath+0x16/0x1b