As documented here and in this thread , spinning up julia with a certain number of threads, let us say N, and then starting (N-1) tasks does not necessarily mean that all the tasks will have a thread to run on. It appears that julia uses some of those threads for other purposes, and some of the task…

What is julia doing with your threads?

carstenbauer February 11, 2024, 6:20am 6

MacOS simply doesn’t allow users to pin threads. If it would, I’d immediately add support for it to ThreadPinning.jl. Probably never going to happen though given that Apple has even removed thread affinity control features in the past.

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What is julia doing with your threads?

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