Refs #216. Revert the default value of GEMM_MULTITHREAD_THRESHOLD to 4.

Makefile.rule

@@ -107,8 +107,8 @@ VERSION = 0.2.6
 
 # If any gemm arguement m, n or k is less or equal this threshold, gemm will be execute 
 # with single thread. You can use this flag to avoid the overhead of multi-threading 
-# in small matrix sizes. The default value is 50.
-# GEMM_MULTITHREAD_THRESHOLD = 50
+# in small matrix sizes. The default value is 4.
+# GEMM_MULTITHREAD_THRESHOLD = 4
 
 # If you need santy check by comparing reference BLAS. It'll be very
 # slow (Not implemented yet).

Makefile.system

@@ -53,7 +53,7 @@ GETARCH_FLAGS	+= -DUSE64BITINT
 endif
 
 ifndef GEMM_MULTITHREAD_THRESHOLD
-GEMM_MULTITHREAD_THRESHOLD=50
+GEMM_MULTITHREAD_THRESHOLD=4
 endif
 GETARCH_FLAGS	+= -DGEMM_MULTITHREAD_THRESHOLD=$(GEMM_MULTITHREAD_THRESHOLD)