From a9e8fa06bf11f174f339151a08978bcb3d49b59e Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Fri, 25 Jul 2025 15:15:46 +0200
Subject: [PATCH] Introduce a (crude) threshold to multithreading

---
 interface/trmv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/interface/trmv.c b/interface/trmv.c
index 2e52527a3c..029a83499d 100644
--- a/interface/trmv.c
+++ b/interface/trmv.c
@@ -219,7 +219,10 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo,
 
 #ifdef SMP
   nthreads = num_cpu_avail(2);
-
+  
+  if (n < 50 ) nthreads = 1;
+  if (nthreads > 2 && n < 500) nthreads = 2;
+	
   if (nthreads == 1) {
 #endif