VirtualBox

Opened 8 years ago

Last modified 8 years ago

#15420 closed defect

Running a VM on Linux forces the kernel to call exit_dns_resolver a lot — at Version 1

Reported by: rtvd Owned by:
Component: other Version: VirtualBox 5.0.20
Keywords: high cpu usage exit_dns_resolver Cc:
Guest type: all Host type: Linux

Description (last modified by Frank Mehnert)

I have a Linux system with VirtualBox 5.0.20 r106931.

Starting any VM (either Linux or Illumos) shows that a lot of time is spent in a strange part of Linux kernel, the "exit_dns_resolver" function. It is so severe that approximately 80-90% is spent just in that function.

As soon as I stop the VMs the situation returns back to norm.

perf record shows the following traces:

    32.70%    32.70%  EMT-0           [kernel.kallsyms]            [k] exit_dns_resolver                                                                                                                  
                     |
                     ---exit_dns_resolver
                        |          
                        |--99.71%-- __GI___ioctl
                        |          |          
                        |          |--99.65%-- 0x104492
                        |          |          0x92eb4
                        |          |          0x8fdbf
                        |          |          0xfe7ec
                        |          |          0xfff1c
                        |          |          0x17b35c
                        |          |          start_thread
                        |           --0.35%-- [...]
                         --0.29%-- [...]

    27.18%    27.18%  EMT-1           [kernel.kallsyms]            [k] exit_dns_resolver                                                                                                                  
                     |
                     ---exit_dns_resolver
                        |          
                        |--99.71%-- __GI___ioctl
                        |          |          
                        |          |--99.65%-- 0x104492
                        |          |          0x92eb4
                        |          |          0x8fdbf
                        |          |          0xfe7ec
                        |          |          0xfff1c
                        |          |          0x17b35c
                        |          |          start_thread
                        |           --0.35%-- [...]
                         --0.29%-- [...]

    26.52%    26.52%  EMT-2           [kernel.kallsyms]            [k] exit_dns_resolver                                                                                                                  
                     |
                     ---exit_dns_resolver
                        |          
                        |--99.68%-- __GI___ioctl
                        |          |          
                        |          |--99.44%-- 0x104492
                        |          |          0x92eb4
                        |          |          0x8fdbf
                        |          |          0xfe7ec
                        |          |          0xfff1c
                        |          |          0x17b35c
                        |          |          start_thread
                        |          |          
                        |           --0.56%-- SUPR3CallVMMR0Ex
                        |                     |          
                        |                     |--79.82%-- 0xfd6ab
                        |                     |          0xfe583
                        |                     |          0x8fcb5
                        |                     |          0xfe7ec
                        |                     |          0xfff1c
                        |                     |          0x17b35c
                        |                     |          start_thread
                        |                     |          
                        |                      --20.18%-- 0x4a23
                        |                                |          
                        |                                |--99.86%-- 0x4ffb
                        |                                |          0xf1803
                        |                                |          TMR3TimerQueuesDo
                        |                                |          |          
                        |                                |          |--91.19%-- 0xfd5b9
                        |                                |          |          0xfe583
                        |                                |          |          0x8fcb5
                        |                                |          |          0xfe7ec
                        |                                |          |          0xfff1c
                        |                                |          |          0x17b35c
                        |                                |          |          start_thread
                        |                                |          |          
                        |                                |           --8.81%-- 0x8f00f
                        |                                |                     |          
                        |                                |                     |--93.36%-- 0x92f2b
                        |                                |                     |          0x8fdbf
                        |                                |                     |          0xfe7ec
                        |                                |                     |          0xfff1c
                        |                                |                     |          0x17b35c
                        |                                |                     |          start_thread
                        |                                |                     |          
                        |                                |                      --6.64%-- 0x8f9bf
                        |                                |                                0xfe7ec
                        |                                |                                0xfff1c
                        |                                |                                0x17b35c
                        |                                |                                start_thread
                        |                                 --0.14%-- [...]
                         --0.32%-- [...]

Change History (3)

by rtvd, 8 years ago

Attachment: VBox.log added

VBox.log of Illumos

by rtvd, 8 years ago

Attachment: VBox.2.log added

VBox.log of a Linux VM

comment:1 by Frank Mehnert, 8 years ago

Description: modified (diff)
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