On my notebook I have issues with Qt based software.
The notebook use Nvidia Optimus technology and is powered by:
When choosing "intel HD" as rendering board for one Qt application (for exemple Oracle VirtualBox) I have one thread using 100% of one of the 8 virtual cores.
The offending thread is looping on DrvValidateVersion. It seems it is throwing an exception, catched, retry, never ending...
When forçing the application / system to render through Nvidia board I have no issue.
BUT Oracle VirtualBox force use of Intelrender path, probably for virtualisation needs.
I manage to go around by patching the offending DLL. I now have DrvValidateVersion "nop-ing" and returning "true". No more issue.
Intel driver is : 10.18.14.4578
Nvidia driver is : 188.8.131.5233 (2016, unable to install last release "blue screen"...)
Windows 7, 64 bits, last updates
If someone has any better idea, solution...
I have the latest available for the intel chipset. I cannot upgrade the Nvidia ones from nvidia upgrade software because of BSOD ... I have not tried the one availbale on windows update. Last try with result = BSOD took me half a working day to restore to a working release...no time 😞
All Qt sotware concern, even a "hello world" in QML.
For VirtualBox, because of other issues with my dirty patched DLL I had to rollback to the official one but I find that disabling 2D and 3D hardware support in VirtualBox manager give me a "small CPU usage" VM.
I have not the issue on "Intel IGP only" computer. My guess is that it could be linked to Nvidia/Intel auto switching technology because I guess the Nvidia driver stack insert some kind of filter in you driver stack to detect and switch when required.
Kind of problem tricky to deal with and to solve because many tiers involved.
If some log, advanced diag is possible / needed you can ask me everything except " please delete everything and start from a new install". Neither command line nor registry editing are a problem for me, it's my everyday life 😉
Here it is.
Note that I discover during completion of the bug report that the issue has disapeared without any change except than Windows Updates... In fact the DrvValidateVersion is still called "in loop", is still throwing an exception (see attached PNG on next post) but is no more taking one full core.
I do not understand. Could it be linked to Spectre mitigation patch or something like this. I don't know.