Opened 14 years ago
Last modified 10 years ago
#6242 closed defect
VT-x causes massive DPC latency — at Version 9
| Reported by: | maqr | Owned by: | |
|---|---|---|---|
| Component: | VMM | Version: | VirtualBox 3.1.4 |
| Keywords: | DPC, VT-x | Cc: | |
| Guest type: | Linux | Host type: | Windows |
Description (last modified by )
I am running Windows 7 x64 on a q6600 with virtualization enabled in the bios. Whenever my guest (x64 or x86) is under any kind of load (even just booting the Ubuntu installer), I get big DPC latency spikes. This is obviously a problem because it causes choppy audio, video, and generally degrades performance. Once inside the guest OS, this is can be easily reproduced with a simple bash script: while true; do ""; done
I have reproduced this on an i7 920 with the same problem.
Attached is a dpclat screenshot and a dump from xperf. If the ETL would be beneficial in debugging, I could produce one.
The "fix" for me was to install a 32-bit guest and disable VT-x in the vbox options.
Change History (11)
by , 14 years ago
| Attachment: | Untitled.png added |
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comment:1 by , 14 years ago
I just assumed that the jumping issues were normal behaviour. When I run with 2 cores and VT-x (especially when running a 64-bit OS) I get audio choppiness, mouse juddering, and a whole host of other host and guest based performance issues.
comment:2 by , 14 years ago
Yes, this behavior is possible with Windows 7 / x64 and there is already a fix in the trunk. Not sure if the next version or the version after the next version will contain the fix.
comment:3 by , 13 years ago
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
Should be fixed in VBox 3.2 (IIRC) and VBox 4.0.
comment:4 by , 13 years ago
| Resolution: | fixed |
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| Status: | closed → reopened |
im also having quite high dpc latency's with the latest virtual box 4.0.8 this happens under a powerful machine.
I have made a post on the forums already, which describes everything: http://forums.virtualbox.org/viewtopic.php?f=6&t=38561
comment:5 by , 13 years ago
The posting is not 100% clear: What is your host, Windows Server 2003 r2? Or is that your guest?
comment:6 by , 13 years ago
host is windows 7 64 bit(now with sp1), the guest is server 2003 r2 32 bit. I have also tried as guest windows 7 sp1 32 bit, it has the same issue.
ill try a 64 bit guest soon.
comment:7 by , 13 years ago
I tried server 2008 r2(64 bit) as a guest os, the dpc latency might have been a bit lower bit it was still on the high side and this was idle with a clean install.
DPClat screenshot