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 Initial Version
| 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
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%-- [...]


VBox.log of Illumos