From a3354a763096b807e27185d48bd473010acd488b Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Wed, 27 Mar 2024 22:00:30 +0100
Subject: [PATCH] Cap the number of parallel threads

---
 interface/gemm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/interface/gemm.c b/interface/gemm.c
index 4778b641b..0902bc024 100644
--- a/interface/gemm.c
+++ b/interface/gemm.c
@@ -533,8 +533,12 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_TRANSPOSE TransA, enum CBLAS_TRANS
   MNK = (double) args.m * (double) args.n * (double) args.k;
   if ( MNK <= (SMP_THRESHOLD_MIN  * (double) GEMM_MULTITHREAD_THRESHOLD)  )
 	args.nthreads = 1;
-  else
+  else {
 	args.nthreads = num_cpu_avail(3);
+	if (MNK/args.nthreads < SMP_THRESHOLD_MIN*(double)GEMM_MULTITHREAD_THRESHOLD)
+		args.nthreads = MNK/(SMP_THRESHOLD_MIN*(double)GEMM_MULTITHREAD_THRESHOLD);
+  }
+
   args.common = NULL;
 
  if (args.nthreads == 1) {