intel tbb compilation and testing

Question

I am compiling intel tbb community version tbb2017_20161128oss. While compiling it runs few test cases. in one of the test case it gives me the warning ./test_global_control.exe
TBB Warning: The number of workers is currently limited to 0. The request for 1 workers is ignored. Further requests for more workers will be silently ignored until the limit changes.

What does this warning mean for my platform? Should I refrain from using certain components of ITBB?

Answer 1

Usually for TBB tests you can ignore run-time warnings starting from "TBB warning". Generally, these warnings are to tell programmers that they possibly use TBB sub-optimally or incorrectly. In the tests, however, the library is used in very complicated ways, and so sometimes warnings are issued.

This particular warning tells that a program first has limited the number of worker threads allowed to use, and then tries to request more workers than the limit allows. For the test, it's important to check that the behavior is correct in such corner cases; but the warning is outside of its control.

In real applications, these warnings can help diagnosing unexpected situations, and so should not be ignored.