High CPU usage with idling guest induced by RTC interrupts
|Reported by:||Nerijus||Owned by:|
|Guest type:||Windows||Host type:||other|
Description (last modified by )
Bug possibly related to: #1884
Occurs on both Vbox 2.1.4 and 2.2.0 Beta2
With Windows 7 guest, and possibly Windows Vista, Windows XP SP3, Windows Server 2008, Windows Server 2008 R2 guests.
- MS SQL server 2008 (express or not),
- SQL server 2005 SP3
- Google Chrome
- Or possibly another application which uses 70h interrupts for timing
virtual box uses ~60-70% of single CPU, while guest OS is almost idle.
What was expected to happen: Host should be almost idle too.
Upon further investigation, it appears that these programs use "Real-Time Clock Interrupt", which fires 1024 times per second.
Problem with SQL server 2008: Forum thread: http://forums.virtualbox.org/viewtopic.php?f=2&t=15668
Same thing happens with Google Chrome. Bug ticket: http://www.virtualbox.org/ticket/1884
TwinCat Forum thread: http://forums.virtualbox.org/viewtopic.php?f=2&t=12941
How problem can be observed with Windows 7 guest (and possibly other guests):
- Open "perfmon", and add "Processor->Interupts/sec" counter to monitor.
- Start Google Chrome (or another mentioned application), and wait for it to finish initialization.
- Watch interrupt count to increase by 1024 per second. This is expected. Guest remains idle.
- However, on host, CPU usage increase significantly.
Change History (34)
comment:10 by , 15 years ago
|Summary:||High CPU usage with idling guest when 70h interrupts are in use → High CPU usage with idling guest induced by RTC interrupts|