[Openmp-commits] [openmp] [OpenMP] Fix hyper barrier performance issue (PR #195473)

Terry Wilmarth via Openmp-commits openmp-commits at lists.llvm.org
Wed May 6 06:32:09 PDT 2026


TerryLWilmarth wrote:

> I think, aggressive active waiting mainly makes sense on otherwise empty systems. Yielding in the barrier can reduce context switches in the middle of computation.
> 
> A better option might be to allow changing the OpenMP wait policy at runtime (i.e. introduce omp_get/set_wait_policy calls), so that the application can encode the preferred behavior.

I agree.  Also, simply using the already available kmp_set_blocktime inside the application gets you most of the way there without any changes to the runtime.  But I agree it would be nice to have the API to set wait policy at runtime too.

https://github.com/llvm/llvm-project/pull/195473


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