common : add common_print_available_devices() (#26170)

Signed-off-by: Adrien Gallouët <angt@huggingface.co>

common/arg.cpp

@@ -1061,6 +1061,31 @@ static std::vector<ggml_backend_dev_t> parse_device_list(const std::string & val
     return devices;
 }
 
+void common_print_available_devices() {
+    constexpr size_t MiB = 1024 * 1024;
+    std::vector<ggml_backend_dev_t> devices;
+
+    ggml_backend_load_all();
+
+    for (size_t i = 0; i < ggml_backend_dev_count(); ++i) {
+        auto * dev = ggml_backend_dev_get(i);
+        if (ggml_backend_dev_type(dev) != GGML_BACKEND_DEVICE_TYPE_CPU) {
+            devices.push_back(dev);
+        }
+    }
+    printf("Available devices:\n");
+
+    if (devices.empty()) {
+        printf("  (none)\n");
+        return;
+    }
+    for (auto * dev : devices) {
+        size_t free, total;
+        ggml_backend_dev_memory(dev, &free, &total);
+        printf("  %s: %s (%zu MiB, %zu MiB free)\n", ggml_backend_dev_name(dev), ggml_backend_dev_description(dev), total / MiB, free / MiB);
+    }
+}
+
 static void add_rpc_devices(const std::string & servers) {
     auto rpc_servers = string_split<std::string>(servers, ',');
     if (rpc_servers.empty()) {
@@ -2588,20 +2613,7 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         {"--list-devices"},
         "print list of available devices and exit",
         [](common_params &) {
-            ggml_backend_load_all();
+            common_print_available_devices();
-            std::vector<ggml_backend_dev_t> devices;
-            for (size_t i = 0; i < ggml_backend_dev_count(); ++i) {
-                auto * dev = ggml_backend_dev_get(i);
-                if (ggml_backend_dev_type(dev) != GGML_BACKEND_DEVICE_TYPE_CPU) {
-                    devices.push_back(dev);
-                }
-            }
-            printf("Available devices:\n");
-            for (auto * dev : devices) {
-                size_t free, total;
-                ggml_backend_dev_memory(dev, &free, &total);
-                printf("  %s: %s (%zu MiB, %zu MiB free)\n", ggml_backend_dev_name(dev), ggml_backend_dev_description(dev), total / 1024 / 1024, free / 1024 / 1024);
-            }
             exit(0);
         }
     ));

common/arg.h

@@ -123,6 +123,9 @@ struct common_params_context {
 // if one argument has invalid value, it will automatically display usage of the specific argument (and not the full usage message)
 bool common_params_parse(int argc, char ** argv, common_params & params, llama_example ex, void(*print_usage)(int, char **) = nullptr);
 
+// load all backends and print the list of available (non-CPU) devices to stdout
+void common_print_available_devices();
+
 // parse input arguments from CLI into a map
 bool common_params_to_map(int argc, char ** argv, llama_example ex, std::map<common_arg, std::string> & out_map);
 

tools/llama-bench/llama-bench.cpp

@@ -670,22 +670,7 @@ static cmd_params parse_cmd_params(int argc, char ** argv) {
                     break;
                 }
             } else if (arg == "--list-devices") {
-                std::vector<ggml_backend_dev_t> devices;
+                common_print_available_devices();
-                for (size_t i = 0; i < ggml_backend_dev_count(); ++i) {
-                    auto * dev = ggml_backend_dev_get(i);
-                    if (ggml_backend_dev_type(dev) != GGML_BACKEND_DEVICE_TYPE_CPU) {
-                        devices.push_back(dev);
-                    }
-                }
-                printf("Available devices:\n");
-                if (devices.empty()) {
-                    printf("  (none)\n");
-                }
-                for (auto * dev : devices) {
-                    size_t free, total;
-                    ggml_backend_dev_memory(dev, &free, &total);
-                    printf("  %s: %s (%zu MiB, %zu MiB free)\n", ggml_backend_dev_name(dev), ggml_backend_dev_description(dev), total / 1024 / 1024, free / 1024 / 1024);
-                }
                 exit(0);
             } else if (arg == "-t" || arg == "--threads") {
                 if (++i >= argc) {