From b865e80c2f0b3aaf4afe695da305a28f6b37deae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20T=C3=B3th?= <michal.toth@opm-op.com>
Date: Wed, 8 Jan 2025 14:39:30 +0100
Subject: [PATCH] Set limit to the number of threads if it is unset when we ask
 for the number.

---
 opm/simulators/flow/Main.hpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/opm/simulators/flow/Main.hpp b/opm/simulators/flow/Main.hpp
index d4e5b2889..e704f3d29 100644
--- a/opm/simulators/flow/Main.hpp
+++ b/opm/simulators/flow/Main.hpp
@@ -731,6 +731,9 @@ private:
                     std::cout << ("Warning: Invalid value for OMP_NUM_THREADS environment variable.") << std::endl;
                 }
             }
+        } else {
+            // Set a limit to OMP threads. Defaults can saturate the whole machine.
+            omp_set_num_threads(threads);
         }
 
         first_time = false;