GitLab runner for Windows causes high CPU load on KVM host

I have GitLab Runner 10.2.0 running on Windows 2016 in KVM via libvirt on Debian 9. When GitLab runnner is running I see a CPU usage on the host of 30%-40%. The task manager on the Windows Server doesn't show any high CPU usage.

The reason for the high load on the host seems to be a huge number of context switches. dstat reports about 7k context switches. Stopping GitLab Runner makes the context switches drop to around 1.6k and interrupts to around 600. With the Runner running:

----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| read  writ| recv  send|  in   out | int   csw 
  4   5  91   0   0   0|   0    16k|2553B 3180B|   0     0 |1667  7299 
  7   5  87   0   0   1|   0     0 |1760B 3265B|   0     0 |1903  7369 
  5   6  89   0   0   0|   0    44k|5944B 5917B|   0     0 |1803  7299 
  5   5  89   0   0   0|   0    16k|1662B 2536B|   0     0 |1913  7271

With the Runner stopped:

----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system--
usr sys idl wai hiq siq| read  writ| recv  send|  in   out | int   csw 
  2   1  97   0   0   0|   0    16k|3418B 3846B|   0     0 | 695  1677 
  1   1  95   3   0   0|   0    16M|4484B 5720B|   0     0 | 696  1691 
  4   1  95   0   0   1|   0     0 | 122B  720B|   0     0 | 667  1529

In /proc/interrupts I can see that most of these interrupts seem to be timer interrupts:

# cat /proc/interrupts | grep LOC; sleep 1; cat /proc/interrupts | grep LOC;
LOC:  214735335  229250283  229962515  214008402   Local timer interrupts
LOC:  214735837  229250667  229962913  214008715   Local timer interrupts

I found out that GitLab runner is the cause by running powercfg energy monitoring on the Windows Server with powercfg -energy duration 5. It reports the following:

Platform Timer Resolution:Outstanding Timer Request
A program or service has requested a timer resolution smaller than the platform maximum timer resolution.
Requested Period	10000
Requesting Process ID	2548
Requesting Process Path	\Device\HarddiskVolume2\GitLab-Runner\gitlab-runner.exe

There already was a similar issue (#976 (closed)) some time ago but no real solution was found. Maybe the information regarding the timing stuff helps to track it down.