From 5e1974693a00b26ba876a565fbfb73df39f9c6d6 Mon Sep 17 00:00:00 2001
From: craig-warren <craig_warren@me.com>
Date: Sun, 10 Dec 2023 23:03:50 +0000
Subject: [PATCH] Manual gc

---
 gprMax/contexts.py | 13 ++++++++++---
 gprMax/updates.py  |  8 ++++++--
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/gprMax/contexts.py b/gprMax/contexts.py
index c174de4c..13506713 100644
--- a/gprMax/contexts.py
+++ b/gprMax/contexts.py
@@ -82,10 +82,14 @@ class Context:
             if not config.sim_config.args.geometry_only:
                 solver = create_solver(G)
                 model.solve(solver)
+                del solver, model
 
             if not config.sim_config.args.geometry_fixed:
-                del solver, model, G
-                gc.collect()
+                # Manual garbage collection required to stop memory leak on GPUs 
+                # when using pycuda
+                del G
+            
+            gc.collect()
 
         self.tsimend = timer()
         self.print_sim_time_taken()
@@ -147,8 +151,11 @@ class MPIContext(Context):
         if not config.sim_config.args.geometry_only:
             solver = create_solver(G)
             model.solve(solver)
+            del solver, model
 
-        del solver, model, G
+        # Manual garbage collection required to stop memory leak on GPUs when
+        # using pycuda
+        del G
         gc.collect()
 
     def run(self):
diff --git a/gprMax/updates.py b/gprMax/updates.py
index b2e93698..fad7aab4 100644
--- a/gprMax/updates.py
+++ b/gprMax/updates.py
@@ -17,6 +17,7 @@
 # along with gprMax.  If not, see <http://www.gnu.org/licenses/>.
 
 import logging
+import subprocess
 from importlib import import_module
 
 import numpy as np
@@ -753,8 +754,11 @@ class CUDAUpdates:
             Memory (RAM) used on GPU.
         """
         if iteration == self.grid.iterations - 1:
-            # Total minus free memory in current context
-            return self.drv.mem_get_info()[1] - self.drv.mem_get_info()[0]
+            mem_used = subprocess.check_output(["nvidia-smi", "--query-gpu=memory.used"], 
+                                               shell=False, stderr=subprocess.STDOUT)
+            return mem_used
+            # # Total minus free memory in current context
+            # return self.drv.mem_get_info()[1] - self.drv.mem_get_info()[0]
 
     def calculate_solve_time(self):
         """Calculates solving time for model."""