Threads.@spawn tasks clash with BLAS thread counts
Threads.@spawn tasks compete with BLAS threads, and changing the BLAS thread count inside tasks races.
Tier II · Emerging Problems that are still building up.
4 public reports · first reported 6 October 2026 · last reported 9 October 2026
What's going wrong
Julia users running parallel loops with Threads.@spawn report that their tasks compete with BLAS threads for the same CPU cores, which slows numerical code.
AI-assisted: written with the help of AI from the reports. The idea report has the full summary.
In the idea report
- The full summary.
- The products the 4 reports are about, and how many came each month.
- Related problems.
No business has been found with this problem yet, so the report has no contacts. All sales are final — no refunds. Pricing.