From cc1147d74a43d30f628428e945ed27b384eba3fb Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Fri, 30 Aug 2024 12:42:09 +0200
Subject: [PATCH] explain workdaround

---
 src/auxiliary/math.jl | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/auxiliary/math.jl b/src/auxiliary/math.jl
index fa816da9a1e..8f442a5b220 100644
--- a/src/auxiliary/math.jl
+++ b/src/auxiliary/math.jl
@@ -284,6 +284,11 @@ end
 # when using `@fastmath`, which we also get from
 # [Fortran](https://godbolt.org/z/Yrsa1js7P)
 # or [C++](https://godbolt.org/z/674G7Pccv).
+#
+# Note however that such a custom reimplementation can cause incompatibilites with other
+# packages. Currently we are affected by an issue with MPI.jl on ARM, see
+# https://github.com/trixi-framework/Trixi.jl/issues/1922
+# The workaround is to resort to Base.min / Base.max when using MPI reductions.
 """
     Trixi.max(x, y, ...)