server: support load model on startup, support preset-only options (#18206)

* server: support autoload model, support preset-only options

* add docs

* load-on-startup

* fix

* Update common/arg.cpp

Co-authored-by: Pascal <admin@serveurperso.com>

---------

Co-authored-by: Pascal <admin@serveurperso.com>

common/arg.cpp

@@ -96,6 +96,11 @@ common_arg & common_arg::set_sparam() {
     return *this;
 }
 
+common_arg & common_arg::set_preset_only() {
+    is_preset_only = true;
+    return *this;
+}
+
 bool common_arg::in_example(enum llama_example ex) {
     return examples.find(ex) != examples.end();
 }
@@ -3494,3 +3499,24 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
 
     return ctx_arg;
 }
+
+void common_params_add_preset_options(std::vector<common_arg> & args) {
+    // arguments below won't be treated as CLI args, only preset options
+    args.push_back(common_arg(
+        {"load-on-startup"}, "NAME",
+        "in server router mode, autoload this model on startup",
+        [](common_params &, const std::string &) { /* unused */ }
+    ).set_env(COMMON_ARG_PRESET_LOAD_ON_STARTUP).set_preset_only());
+
+    // args.push_back(common_arg(
+    //     {"pin"},
+    //     "in server router mode, do not unload this model if models_max is exceeded",
+    //     [](common_params &) { /* unused */ }
+    // ).set_preset_only());
+
+    // args.push_back(common_arg(
+    //     {"unload-idle-seconds"}, "SECONDS",
+    //     "in server router mode, unload models idle for more than this many seconds",
+    //     [](common_params &, int) { /* unused */ }
+    // ).set_preset_only());
+}

common/arg.h

@@ -8,6 +8,9 @@
 #include <vector>
 #include <cstring>
 
+// pseudo-env variable to identify preset-only arguments
+#define COMMON_ARG_PRESET_LOAD_ON_STARTUP "__PRESET_LOAD_ON_STARTUP"
+
 //
 // CLI argument parsing
 //
@@ -22,6 +25,7 @@ struct common_arg {
     const char * env          = nullptr;
     std::string help;
     bool is_sparam = false; // is current arg a sampling param?
+    bool is_preset_only = false; // is current arg preset-only (not treated as CLI arg)
     void (*handler_void)   (common_params & params) = nullptr;
     void (*handler_string) (common_params & params, const std::string &) = nullptr;
     void (*handler_str_str)(common_params & params, const std::string &, const std::string &) = nullptr;
@@ -70,6 +74,7 @@ struct common_arg {
     common_arg & set_excludes(std::initializer_list<enum llama_example> excludes);
     common_arg & set_env(const char * env);
     common_arg & set_sparam();
+    common_arg & set_preset_only();
     bool in_example(enum llama_example ex);
     bool is_exclude(enum llama_example ex);
     bool get_value_from_env(std::string & output) const;
@@ -114,9 +119,13 @@ struct common_params_context {
 bool common_params_parse(int argc, char ** argv, common_params & params, llama_example ex, void(*print_usage)(int, char **) = nullptr);
 
 // parse input arguments from CLI into a map
-// TODO: support repeated args in the future
 bool common_params_to_map(int argc, char ** argv, llama_example ex, std::map<common_arg, std::string> & out_map);
 
+// populate preset-only arguments
+// these arguments are not treated as command line arguments
+// see: https://github.com/ggml-org/llama.cpp/issues/18163
+void common_params_add_preset_options(std::vector<common_arg> & args);
+
 // initialize argument parser context - used by test-arg-parser and preset
 common_params_context common_params_parser_init(common_params & params, llama_example ex, void(*print_usage)(int, char **) = nullptr);
 

common/preset.cpp

@@ -24,7 +24,14 @@ std::vector<std::string> common_preset::to_args(const std::string & bin_path) co
     }
 
     for (const auto & [opt, value] : options) {
-        args.push_back(opt.args.back()); // use the last arg as the main arg
+        if (opt.is_preset_only) {
+            continue; // skip preset-only options (they are not CLI args)
+        }
+
+        // use the last arg as the main arg (i.e. --long-form)
+        args.push_back(opt.args.back());
+
+        // handle value(s)
         if (opt.value_hint == nullptr && opt.value_hint_2 == nullptr) {
             // flag option, no value
             if (common_arg_utils::is_falsey(value)) {
@@ -224,8 +231,10 @@ static std::string parse_bool_arg(const common_arg & arg, const std::string & ke
 }
 
 common_preset_context::common_preset_context(llama_example ex)
-    : ctx_params(common_params_parser_init(default_params, ex)),
+        : ctx_params(common_params_parser_init(default_params, ex)) {
-      key_to_opt(get_map_key_opt(ctx_params)) {}
+    common_params_add_preset_options(ctx_params.options);
+    key_to_opt = get_map_key_opt(ctx_params);
+}
 
 common_presets common_preset_context::load_from_ini(const std::string & path, common_preset & global) const {
     common_presets out;

tests/test-arg-parser.cpp

@@ -16,6 +16,7 @@ int main(void) {
     for (int ex = 0; ex < LLAMA_EXAMPLE_COUNT; ex++) {
         try {
             auto ctx_arg = common_params_parser_init(params, (enum llama_example)ex);
+            common_params_add_preset_options(ctx_arg.options);
             std::unordered_set<std::string> seen_args;
             std::unordered_set<std::string> seen_env_vars;
             for (const auto & opt : ctx_arg.options) {

tools/server/README.md

@@ -1480,6 +1480,9 @@ The precedence rule for preset options is as follows:
 2. **Model-specific options** defined in the preset file (e.g. `[ggml-org/MY-MODEL...]`)
 3. **Global options** defined in the preset file (`[*]`)
 
+We also offer additional options that are exclusive to presets (these aren't treated as command-line arguments):
+- `load-on-startup` (boolean): Controls whether the model loads automatically when the server starts
+
 ### Routing requests
 
 Requests are routed according to the requested model name.

tools/server/server-models.cpp

@@ -226,6 +226,26 @@ void server_models::load_models() {
             SRV_INF("  %c %s\n", has_custom ? '*' : ' ', name.c_str());
         }
     }
+
+    // load any autoload models
+    std::vector<std::string> models_to_load;
+    for (const auto & [name, inst] : mapping) {
+        std::string val;
+        if (inst.meta.preset.get_option(COMMON_ARG_PRESET_LOAD_ON_STARTUP, val)) {
+            models_to_load.push_back(name);
+        }
+    }
+    if ((int)models_to_load.size() > base_params.models_max) {
+        throw std::runtime_error(string_format(
+            "number of models to load on startup (%zu) exceeds models_max (%d)",
+            models_to_load.size(),
+            base_params.models_max
+        ));
+    }
+    for (const auto & name : models_to_load) {
+        SRV_INF("(startup) loading model %s\n", name.c_str());
+        load(name);
+    }
 }
 
 void server_models::update_meta(const std::string & name, const server_model_meta & meta) {

tools/server/server-models.h

@@ -103,27 +103,29 @@ public:
 
     void load_models();
 
-    // check if a model instance exists
+    // check if a model instance exists (thread-safe)
     bool has_model(const std::string & name);
 
-    // return a copy of model metadata
+    // return a copy of model metadata (thread-safe)
     std::optional<server_model_meta> get_meta(const std::string & name);
 
-    // return a copy of all model metadata
+    // return a copy of all model metadata (thread-safe)
     std::vector<server_model_meta> get_all_meta();
 
+    // load and unload model instances
+    // these functions are thread-safe
     void load(const std::string & name);
     void unload(const std::string & name);
     void unload_all();
 
-    // update the status of a model instance
+    // update the status of a model instance (thread-safe)
     void update_status(const std::string & name, server_model_status status);
 
-    // wait until the model instance is fully loaded
+    // wait until the model instance is fully loaded (thread-safe)
     // return when the model is loaded or failed to load
     void wait_until_loaded(const std::string & name);
 
-    // load the model if not loaded, otherwise do nothing
+    // load the model if not loaded, otherwise do nothing (thread-safe)
     // return false if model is already loaded; return true otherwise (meta may need to be refreshed)
     bool ensure_model_loaded(const std::string & name);