From 244147495ac672015af6a87ad51b60fd1a0ba603 Mon Sep 17 00:00:00 2001
From: Martin Kroeker <martin@ruby.chemie.uni-freiburg.de>
Date: Thu, 23 Mar 2023 23:13:02 +0100
Subject: [PATCH] Do not use multithreading for small workloads

---
 interface/symv.c  | 3 +++
 interface/syr2k.c | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/interface/symv.c b/interface/symv.c
index 07bd200227..1f23ce4ee5 100644
--- a/interface/symv.c
+++ b/interface/symv.c
@@ -180,6 +180,9 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo, blasint n, FLOAT alpha,
   buffer = (FLOAT *)blas_memory_alloc(1);
 
 #ifdef SMP
+  if (n <200)
+	  nthreads=1;
+  else
   nthreads = num_cpu_avail(2);
 
   if (nthreads == 1) {
diff --git a/interface/syr2k.c b/interface/syr2k.c
index a72330c0bd..47df7f89f0 100644
--- a/interface/syr2k.c
+++ b/interface/syr2k.c
@@ -368,6 +368,9 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo, enum CBLAS_TRANSPOSE Tr
   mode |= (uplo  << BLAS_UPLO_SHIFT);
 
   args.common = NULL;
+  if (args.n*args.k <1000)
+	  args.nthreads =1 ;
+  else
   args.nthreads = num_cpu_avail(3);
 
   if (args.nthreads == 1) {