From 021b18335ca5f28df1029b2dc33ff027be0e8836 Mon Sep 17 00:00:00 2001
From: Fabian Boehm <FHomborg@gmail.com>
Date: Tue, 14 Jan 2025 17:52:17 +0100
Subject: [PATCH] cmake/Tests: Default to half the cores

Saturating all cores easily leads to timeouts.

The system might be doing something else, and it only leaves at most
one core per-test.

E.g. this will cause 90% of runs to fail on a raspberry pi 4.

Note that we set CTEST_PARALLEL_LEVEL on our CI machines anyway, so
this will not affect them.
---
 cmake/Tests.cmake | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cmake/Tests.cmake b/cmake/Tests.cmake
index b085c2ba7..56d150417 100644
--- a/cmake/Tests.cmake
+++ b/cmake/Tests.cmake
@@ -8,7 +8,8 @@ if(NOT CTEST_PARALLEL_LEVEL)
   if(NOT CTEST_PARALLEL_LEVEL)
     include(ProcessorCount)
     ProcessorCount(CORES)
-    set(CTEST_PARALLEL_LEVEL ${CORES})
+    math(EXPR halfcores "${CORES} / 2")
+    set(CTEST_PARALLEL_LEVEL ${halfcores})
   endif()
 endif()