Comment by 1000100_1000101

I'm not the original poster, but I ran into something similar late in Win 7 (Win 8 was in beta at the time). We had some painting software, and we used open-MP to work on each scan-line of a brush in parallel.

It worked fine on Mac. On Windows though, if you let it use as many threads as there were CPUs, it would nearly 100% of the time fail before making it through our test suite. Something in scheduling the work would deadlock. It was more likely to fail if anything was open besides the app. Basically, a brush stoke that should complete in a tenth of a second would stall. If you waited 30-60 minutes (yes minutes), it would recover and continue.

I vaguely recall we used the Intel compiler implementation of OpenMP, not what comes with MSVC, so the fault wasn't necessarily a Microsoft issue, but could still be a kernel issue.

I left that company later that year, and MS rolled out Windows 8. No idea how long that bug stuck around.