Very slow guest OS performance when Windows XP Guest guest has more than 1 VCPU

[Artem S. Tashkinov]

My hardware and software configuration is mentioned in bug 12381.

When I enabled more than 1CPU for my guest OS, it becomes extremely slow - my favorite test is when I simply run mspaint.exe from Win + R dialog.

When I have just one VCPU enabled, mspaint runs inconstantly.

When I have two or more VCPUs enabled, mspaint takes two full seconds to start.

The guest OS is completely (!) idle - I have no active applications running, the Windows Update service is disabled altogether.

[Artem S. Tashkinov]

VBox.log

[Artem S. Tashkinov]

I've forgotten to change the ticket parameters:

Host: Linux i686
Guest: Windows XP, i686

[Frank Mehnert]

Is this a regression from your point of view or didn't you test this setup with an older version of VirtualBox before?

[Artem S. Tashkinov]

It affects both VBox 4.2.18 and 4.3.3-SVN, and I cannot check earlier versions since VBox 4.1.x is incompatible with recent Linux kernels.

I've never run WinXP (or any other guests) with more than 1VCPU so I cannot say if it's a regression or it's always been like that.

I can record a video if you're interested, but this bug can be easily reproduced (like I said my guest has zero additional applications installed - I usually test new software thus I always run with snapshots and subsequently revert to a clean slate every time I finish working with my guest).

[aeichner]

Please reopen if still relevant with a recent VirtualBox release.

[Artem S. Tashkinov]

Gonna reopen this one since it's easily reproducible in VirtualBox 5.1.8

Here's a sample bat file for Windows XP:

@echo off
for /L %%n in (1,1,80) do start mspaint

In a guest with one virtual CPU, this script takes 6 seconds to run (i.e. launch 80 mspaint instances)

In a guest with two or more virtual CPUs this script takes 24 seconds to run, i.e. it becomes 4 (four!) times slower.

Configuration:

Host: Linux 4.8.8 64 vanilla, CentOS 6 64, VirtualBox 5.1.8 binary from Oracle (VirtualBox-5.1.8-111374-Linux_amd64.run), binary NVIDIA drivers installed, GPU: GTX 1060 6GB
Guest: Windows XP SP3 Professional 32bit vanilla: no patches, no updates, no additional software. Swap disabled. 1536MB RAM
Latest Guest Additions installed (doesn't matter if they're installed or not)

[Socratis]

I can confirm this behavior with the test batch provided.

• Host: OSX 10.9.5
• Guest: WinXP SP3 fully updated
• VirtualBox: 5.1.9 r111957 (Qt5.6.2)
• Test: 4 CPUs (original installation) vs 1 CPU

Nothing suspicious in the logs, but if you want them, simply ask. They're almost identical, except of course where the #CPUs differs.

This reminds me of an old ticket of mine from 2013, #12536.

[Artem S. Tashkinov]

Replying to socratis:

This reminds me of an old ticket of mine from 2013, #12536.

Yep, in some ways these two tickets look similar, except when the guest has just one virtual CPU, IOAPIC doesn't have any negative effect.