use process_time to measure only process execution time

gprMax/model_build_run.py

@@ -22,7 +22,7 @@ import itertools
 import os
 import psutil
 import sys
-from time import perf_counter
+from time import process_time
 
 from colorama import init
 from colorama import Fore
@@ -417,7 +417,7 @@ def solve_cpu(currentmodelrun, modelend, G):
         tsolve (float): Time taken to execute solving
     """
 
-    tsolvestart = perf_counter()
+    tsolvestart = process_time()
 
     for iteration in tqdm(range(G.iterations), desc='Running simulation, model ' + str(currentmodelrun) + '/' + str(modelend), ncols=get_terminal_width() - 1, file=sys.stdout, disable=not G.progressbars):
         # Store field component values for every receiver and transmission line
@@ -467,7 +467,7 @@ def solve_cpu(currentmodelrun, modelend, G):
         elif Material.maxpoles > 1:
             update_electric_dispersive_multipole_B(G.nx, G.ny, G.nz, G.nthreads, Material.maxpoles, G.updatecoeffsdispersive, G.ID, G.Tx, G.Ty, G.Tz, G.Ex, G.Ey, G.Ez)
 
-    tsolve = perf_counter() - tsolvestart
+    tsolve = process_time() - tsolvestart
 
     return tsolve