fix: add missing delwin for shader_cores/l2_cache_size/exec_engines, plot_window, and unsigned underflow guard

- free_device_windows: delwin() for shader_cores, l2_cache_size,
  exec_engines (upstream PR Syllo#467 fix/memory-leaks-in-free-device-windows)
- delete_all_windows: delwin() for plots[i].plot_window
  (upstream PR Syllo#468 fix/plot-window-memory-leak)
- nvtop_get_nvlink_info: guard against unsigned underflow in CLI
  throughput delta if hardware counter wraps or resets

Author: danbedford

src/extract_gpuinfo_nvidia.c

@@ -1237,8 +1237,13 @@ unsigned nvtop_get_nvlink_info(struct gpu_info *_gpu_info, struct nvlink_info *n
 
         unsigned long long total_tx = 0, total_rx = 0;
         for (unsigned int link = 0; link < linkCount; link++) {
-          total_tx += cli_tx[link] - gpu_info->nvlink_cli_tx[link];
-          total_rx += cli_rx[link] - gpu_info->nvlink_cli_rx[link];
+          // Guard against unsigned underflow if the hardware counter wraps or resets.
+          // If the new reading is less than the stored reading, skip this link to
+          // avoid a delta near ULLONG_MAX that would produce an absurd throughput spike.
+          if (cli_tx[link] >= gpu_info->nvlink_cli_tx[link])
+            total_tx += cli_tx[link] - gpu_info->nvlink_cli_tx[link];
+          if (cli_rx[link] >= gpu_info->nvlink_cli_rx[link])
+            total_rx += cli_rx[link] - gpu_info->nvlink_cli_rx[link];
         }
         // Raw rate (no smoothing — accuracy is more important than display smoothness)
         gpu_info->smoothed_agg_tx = (unsigned long long)((double)total_tx / delta_s);

src/interface.c

@@ -252,6 +252,13 @@ static void free_device_windows(struct device_window *dwin) {
   delwin(dwin->temperature);
   delwin(dwin->fan_speed);
   delwin(dwin->pcie_info);
+  // Upstream bug: shader_cores, l2_cache_size, exec_engines were allocated with
+  // newwin() in alloc_device_window() but never freed here. This leaks 3 WINDOW
+  // structs per device on every delete_all_windows() call (terminal resize, GPU set change).
+  // Also fixed in upstream PR #467 (fix/memory-leaks-in-free-device-windows).
+  delwin(dwin->shader_cores);
+  delwin(dwin->l2_cache_size);
+  delwin(dwin->exec_engines);
   if (dwin->nvlink_info != NULL)
     delwin(dwin->nvlink_info);
   if (dwin->nvlink_errors != NULL)
@@ -459,6 +466,11 @@ static void delete_all_windows(struct nvtop_interface *dwin) {
   delwin(dwin->process.option_window.option_win);
   for (size_t i = 0; i < dwin->num_plots; ++i) {
     delwin(dwin->plots[i].win);
+    // Upstream bug: plot_window was allocated with newwin() in
+    // initialize_gpu_mem_plot() but never freed here. This leaks one WINDOW
+    // struct per chart on every delete_all_windows() call.
+    // Also fixed in upstream PR #468 (fix/plot-window-memory-leak).
+    delwin(dwin->plots[i].plot_window);
     free(dwin->plots[i].data);
   }
   free_setup_window(&dwin->setup_win);