[SYCL] Add SYCL Backend registry, device and Event Interfaces (#9705)

* implemented missing SYCL event APIs

* sycl : Added device and backend reg interfaces

* Restructured ggml-sycl.cpp

examples/llama-bench/llama-bench.cpp

@@ -151,7 +151,7 @@ static std::string get_gpu_info() {
     int count = ggml_backend_sycl_get_device_count();
     for (int i = 0; i < count; i++) {
         char buf[128];
-        ggml_sycl_get_device_description(i, buf, sizeof(buf));
+        ggml_backend_sycl_get_device_description(i, buf, sizeof(buf));
         id += buf;
         if (i < count - 1) {
             id += "/";

ggml/include/ggml-sycl.h

@@ -19,6 +19,8 @@ extern "C" {
 // backend API
 GGML_API ggml_backend_t ggml_backend_sycl_init(int device);
 
+GGML_API bool ggml_backend_is_sycl(ggml_backend_t backend);
+
 // devide buffer
 GGML_API ggml_backend_buffer_type_t ggml_backend_sycl_buffer_type(int device);
 
@@ -29,14 +31,19 @@ GGML_API ggml_backend_buffer_type_t ggml_backend_sycl_split_buffer_type(const fl
 GGML_API ggml_backend_buffer_type_t ggml_backend_sycl_host_buffer_type(void);
 
 GGML_API void ggml_backend_sycl_print_sycl_devices(void);
-GGML_API void ggml_sycl_get_gpu_list(int *id_list, int max_len);
-GGML_API void ggml_sycl_get_device_description(int device, char *description, size_t description_size);
+GGML_API void ggml_backend_sycl_get_gpu_list(int *id_list, int max_len);
+GGML_API void ggml_backend_sycl_get_device_description(int device,
+                                                       char *description,
+                                                       size_t description_size);
 GGML_API int  ggml_backend_sycl_get_device_count();
 GGML_API void ggml_backend_sycl_get_device_memory(int device, size_t *free, size_t *total);
 
 // SYCL doesn't support registering host memory, keep here for reference
 // GGML_API bool ggml_backend_sycl_register_host_buffer(void * buffer, size_t size);
 // GGML_API void ggml_backend_sycl_unregister_host_buffer(void * buffer);
+
+GGML_API ggml_backend_reg_t ggml_backend_sycl_reg(void);
+
 #ifdef  __cplusplus
 }
 #endif

ggml/src/ggml-backend.cpp

@@ -537,6 +537,10 @@ void * ggml_backend_reg_get_proc_address(ggml_backend_reg_t reg, const char * na
 #include "ggml-metal.h"
 #endif
 
+#ifdef GGML_USE_SYCL
+#include "ggml-sycl.h"
+#endif
+
 #ifdef GGML_USE_VULKAN
 #include "ggml-vulkan.h"
 #endif
@@ -568,6 +572,9 @@ struct ggml_backend_registry {
 #ifdef GGML_USE_METAL
         register_backend(ggml_backend_metal_reg());
 #endif
+#ifdef GGML_USE_SYCL
+        register_backend(ggml_backend_sycl_reg());
+#endif
 #ifdef GGML_USE_VULKAN
         register_backend(ggml_backend_vk_reg());
 #endif
@@ -581,7 +588,7 @@ struct ggml_backend_registry {
         register_backend(ggml_backend_amx_reg());
 #endif
 
-        // TODO: sycl, kompute, cann
+        // TODO: kompute, cann
 
         register_backend(ggml_backend_cpu_reg());
     }
@@ -2254,6 +2261,7 @@ ggml_backend_sched_t ggml_backend_sched_new(
         sched->backends[b] = backends[b];
         sched->bufts[b] = bufts ? bufts[b] : ggml_backend_get_default_buffer_type(backends[b]);
         GGML_ASSERT(ggml_backend_supports_buft(backends[b], sched->bufts[b]));
+
         if (sched->n_copies > 1) {
             for (int c = 0; c < sched->n_copies; c++) {
                 sched->events[b][c] = ggml_backend_event_new(backends[b]->device);

src/llama.cpp

@@ -8,9 +8,7 @@
 #include "ggml-alloc.h"
 #include "ggml-backend.h"
 
-#if defined(GGML_USE_SYCL)
-#  include "ggml-sycl.h"
-#elif defined(GGML_USE_KOMPUTE)
+#if defined(GGML_USE_KOMPUTE)
 #   include "ggml-kompute.h"
 #elif defined(GGML_USE_CANN)
 #   include "ggml-cann.h"
@@ -3422,9 +3420,11 @@ struct llama_lora_adapter {
 static int llama_get_device_count(const llama_model & model) {
     int count = (int) model.devices.size();
 
-#if defined(GGML_USE_SYCL)
-    count += ggml_backend_sycl_get_device_count();
-#elif defined(GGML_USE_CANN)
+#if defined(GGML_USE_RPC)
+    count += (int) model.rpc_servers.size();
+#endif
+
+#if defined(GGML_USE_CANN)
     count += ggml_backend_cann_get_device_count();
 #endif
 
@@ -3445,11 +3445,7 @@ static ggml_backend_buffer_type_t llama_default_buffer_type_cpu(const llama_mode
         }
     }
 
-#if defined(GGML_USE_SYCL)
-    if (host_buffer) {
-        buft = ggml_backend_sycl_host_buffer_type();
-    }
-#elif defined(GGML_USE_CANN)
+#if defined(GGML_USE_CANN)
     if (host_buffer) {
         buft = ggml_backend_cann_host_buffer_type();
     }
@@ -3473,9 +3469,7 @@ static ggml_backend_buffer_type_t llama_default_buffer_type_offload(const llama_
     }
     device -= (int)model.devices.size();
 
-#if defined(GGML_USE_SYCL)
-    buft = ggml_backend_sycl_buffer_type(device);
-#elif defined(GGML_USE_KOMPUTE)
+#if defined(GGML_USE_KOMPUTE)
     buft = ggml_backend_kompute_buffer_type(device);
 #elif defined(GGML_USE_CANN)
     buft = ggml_backend_cann_buffer_type(device);
@@ -3505,12 +3499,6 @@ static ggml_backend_buffer_type_t llama_default_buffer_type_split(const llama_mo
         }
     }
 
-#ifdef GGML_USE_SYCL
-    if (ggml_backend_sycl_get_device_count() > 1) {
-        buft = ggml_backend_sycl_split_buffer_type(tensor_split);
-    }
-#endif
-
     if (buft == nullptr) {
         buft = llama_default_buffer_type_offload(model, fallback_gpu);
     }
@@ -3528,12 +3516,7 @@ static size_t llama_get_device_memory(const llama_model & model, int device) {
         return free;
     }
 
-#if defined(GGML_USE_SYCL)
-    size_t total;
-    size_t free;
-    ggml_backend_sycl_get_device_memory(device, &free, &total);
-    return free;
-#elif defined(GGML_USE_CANN)
+#if defined(GGML_USE_CANN)
     size_t total;
     size_t free;
     ggml_backend_cann_get_device_memory(device, &free, &total);
@@ -19096,7 +19079,7 @@ bool llama_supports_mlock(void) {
 }
 
 bool llama_supports_gpu_offload(void) {
-#if defined(GGML_USE_SYCL) || defined(GGML_USE_KOMPUTE)
+#if defined(GGML_USE_KOMPUTE)
     // Defined when llama.cpp is compiled with support for offloading model layers to GPU.
     return true;
 #else
@@ -19428,29 +19411,7 @@ struct llama_context * llama_new_context_with_model(
             main_gpu -= (int)model->devices.size();
         }
 
-#if defined(GGML_USE_SYCL)
-        // with split_mode LLAMA_SPLIT_MODE_NONE or LLAMA_SPLIT_MODE_ROW, only the main GPU backend is used
-        if (model->split_mode == LLAMA_SPLIT_MODE_NONE || model->split_mode == LLAMA_SPLIT_MODE_ROW) {
-            ggml_backend_t backend = ggml_backend_sycl_init(main_gpu);
-            if (backend == nullptr) {
-                LLAMA_LOG_ERROR("%s: failed to initialize SYCL%d backend\n", __func__, main_gpu);
-                llama_free(ctx);
-                return nullptr;
-            }
-            ctx->backends.push_back(backend);
-        } else {
-            // LLAMA_SPLIT_LAYER requires a backend for each GPU
-            for (int i = 0; i < ggml_backend_sycl_get_device_count(); ++i) {
-                ggml_backend_t backend = ggml_backend_sycl_init(i);
-                if (backend == nullptr) {
-                    LLAMA_LOG_ERROR("%s: failed to initialize SYCL%d for No.%d backend\n", __func__, i, i);
-                    llama_free(ctx);
-                    return nullptr;
-                }
-                ctx->backends.push_back(backend);
-            }
-        }
-#elif defined(GGML_USE_KOMPUTE)
+#if defined(GGML_USE_KOMPUTE)
         if (model->n_gpu_layers > 0) {
             auto * backend = ggml_backend_kompute_init(main_gpu);
             if (backend == nullptr) {