[SYCL] add dev2dev memcpy by SYCL API

docs/backend/SYCL.md

@@ -712,6 +712,7 @@ use 1 SYCL GPUs: [0] with Max compute units:512
 | Name              | Value            | Function                                                                                                                  |
 |-------------------|------------------|---------------------------------------------------------------------------------------------------------------------------|
 | GGML_SYCL_DEBUG   | 0 (default) or 1 | Enable log function by macro: GGML_SYCL_DEBUG                                                                             |
+| GGML_SYCL_DEV2DEV_MEMCPY | 0 (default) or 1 | Choose the SYCL or L0 API in dev2dev memory copy.<br>Value: <br>*  0: SYCL API (default)<br>* 1: L0 API -- L0 API is found to lead to abnormal crash in some case. This debug flag is used to check the issue.|
 | GGML_SYCL_ENABLE_FLASH_ATTN | 1 (default) or 0| Enable Flash-Attention. It can reduce memory usage. The performance impact depends on the LLM.|
 | GGML_SYCL_DISABLE_OPT | 0 (default) or 1 | Disable optimize features for Intel GPUs. (Recommended to 1 for Intel devices older than Gen 10) |
 | GGML_SYCL_DISABLE_GRAPH | 0 or 1 (default) | Disable running computations through SYCL Graphs feature. Disabled by default because SYCL Graph is still on development, no better performance. |
@@ -731,6 +732,7 @@ Pass these via `CXXFLAGS` or add a one-off `#define` to enable a flag on the spo
 | DEBUG_SYCL_POOL | Enable device memory pool logging on teardown. Useful for profiling allocations. |
 | DEBUG_SYCL_MALLOC | Enable verbose per-call logging of device pool alloc/free operations. |
 
+
 ## Design Rule
 
 - Open to all contributors.

ggml/src/ggml-sycl/common.hpp

@@ -62,6 +62,7 @@ extern int g_ggml_sycl_debug;
 extern int g_ggml_sycl_disable_optimize;
 extern int g_ggml_sycl_prioritize_dmmv;
 extern int g_ggml_sycl_enable_flash_attention;
+extern int g_ggml_sycl_dev2dev_memcpy;
 
 
 #if defined(__clang__) && __has_builtin(__builtin_expect)
@@ -126,6 +127,11 @@ enum ggml_sycl_backend_gpu_mode {
   SYCL_MUL_GPU_MODE
 };
 
+enum ggml_sycl_dev2dev_memcpy_mode {
+  DEV2DEV_MEMCPY_SYCL = 0,
+  DEV2DEV_MEMCPY_L0 = 1,
+};
+
 static_assert(sizeof(sycl::half) == sizeof(ggml_fp16_t), "wrong fp16 size");
 
 static void crash() {

ggml/src/ggml-sycl/dpct/helper.hpp

@@ -13,14 +13,14 @@
 #ifndef GGML_SYCL_DPCT_HELPER_HPP
 #define GGML_SYCL_DPCT_HELPER_HPP
 
+#include <cstdlib>
+#include <iostream>
+#include <map>
+
 #include <sycl/sycl.hpp>
 #include <sycl/half_type.hpp>
 #include <oneapi/mkl.hpp>
 
-#include <map>
-
-#include "ggml.h"
-
 #if defined(__linux__)
 #include <sys/mman.h>
 #elif defined(_WIN64)
@@ -43,6 +43,7 @@
 #include <windows.h>
 #endif
 
+
 #define DPCT_COMPATIBILITY_TEMP (900)
 
 #if defined(_MSC_VER)
@@ -59,6 +60,13 @@
 #define __dpct_noinline__ __attribute__((noinline))
 #endif
 
+#define DPCT_UNUSED(x) (void)(x)
+
+inline void _abort(const char * str) {
+    std::cerr << str << std::endl;
+    std::abort();
+}
+
 inline std::string get_device_type_name(const sycl::device &Device) {
     auto DeviceType = Device.get_info<sycl::info::device::device_type>();
     switch (DeviceType) {
@@ -1017,7 +1025,7 @@ namespace dpct
             if (backend == "opencl:cpu") return 4;
             if (backend == "opencl:acc") return 5;
             printf("convert_backend_index: can't handle backend=%s\n", backend.c_str());
-            GGML_ABORT("fatal error");
+            _abort("fatal error");
         }
         static bool compare_backend(std::string &backend1, std::string &backend2) {
             return convert_backend_index(backend1) < convert_backend_index(backend2);
@@ -1426,7 +1434,7 @@ namespace dpct
             if (!size)
                 return sycl::event{};
             return q.memcpy(to_ptr, from_ptr, size, dep_events);
-            GGML_UNUSED(direction);
+            DPCT_UNUSED(direction);
         }
 
         // Get actual copy range and make sure it will not exceed range.
@@ -2092,7 +2100,7 @@ namespace dpct
         if (!size)
             return sycl::event{};
         return q.memcpy(to_ptr, from_ptr, size, dep_events);
-        GGML_UNUSED(direction);
+        DPCT_UNUSED(direction);
     }
 
     // Get actual copy range and make sure it will not exceed range.

ggml/src/ggml-sycl/ggml-sycl.cpp

@@ -86,6 +86,7 @@ int g_ggml_sycl_use_async_mem_op = 0;
 int g_ggml_sycl_use_async_mem_op_requested = 1;
 int g_ggml_sycl_enable_level_zero = 0;
 int g_ggml_sycl_enable_flash_attention = 1;
+int g_ggml_sycl_dev2dev_memcpy = DEV2DEV_MEMCPY_SYCL;
 int g_ggml_sycl_usm_system = 0;
 
 static ggml_sycl_device_info ggml_sycl_init() {
@@ -272,6 +273,11 @@ static void ggml_check_sycl() try {
         g_ggml_sycl_enable_vmm = ggml_sycl_get_env("GGML_SYCL_ENABLE_VMM", 1);
         g_ggml_sycl_prioritize_dmmv = ggml_sycl_get_env("GGML_SYCL_PRIORITIZE_DMMV", 0);
 
+        g_ggml_sycl_dev2dev_memcpy = ggml_sycl_get_env("GGML_SYCL_DEV2DEV_MEMCPY", DEV2DEV_MEMCPY_SYCL);
+        if (g_ggml_sycl_enable_level_zero == 0) {
+            g_ggml_sycl_dev2dev_memcpy = DEV2DEV_MEMCPY_SYCL;
+        }
+
 #ifdef SYCL_FLASH_ATTN
         g_ggml_sycl_enable_flash_attention = ggml_sycl_get_env("GGML_SYCL_ENABLE_FLASH_ATTN", 1);
 #else
@@ -324,8 +330,11 @@ static void ggml_check_sycl() try {
 #endif
 #ifdef GGML_SYCL_SUPPORT_LEVEL_ZERO
         GGML_LOG_INFO("  GGML_SYCL_ENABLE_LEVEL_ZERO: %d\n", g_ggml_sycl_enable_level_zero);
+        GGML_LOG_INFO("  GGML_SYCL_DEV2DEV_MEMCPY: %d\n", g_ggml_sycl_dev2dev_memcpy);
 #else
         GGML_LOG_INFO("  GGML_SYCL_ENABLE_LEVEL_ZERO: Level Zero disabled by compile flag\n");
+        GGML_LOG_INFO("  GGML_SYCL_DEV2DEV_MEMCPY: %d, enable to SYCL API since missing GGML_SYCL_SUPPORT_LEVEL_ZERO\n",
+                      g_ggml_sycl_dev2dev_memcpy);
 #endif
 #if GGML_SYCL_DNNL
         GGML_LOG_INFO("  GGML_SYCL_DISABLE_DNN: %d\n", g_ggml_sycl_disable_dnn);
@@ -598,27 +607,42 @@ static bool ggml_sycl_is_l0_discrete_gpu(int device) {
 
 static void dev2dev_memcpy(int device_dst, sycl::queue &q_dst, int device_src, sycl::queue &q_src, void *ptr_dst,
                     const void *ptr_src, size_t size) {
+
 #ifdef GGML_SYCL_SUPPORT_LEVEL_ZERO
-    // Use Level Zero direct copy for dGPU-to-dGPU transfers.
-    const bool l0_copy_supported = g_ggml_sycl_enable_level_zero &&
-        ggml_sycl_is_l0_discrete_gpu(device_dst) && ggml_sycl_is_l0_discrete_gpu(device_src);
-    if (l0_copy_supported) {
-        auto ze_ctx = sycl::get_native<sycl::backend::ext_oneapi_level_zero>(q_dst.get_context());
-        auto ze_dev = sycl::get_native<sycl::backend::ext_oneapi_level_zero>(q_dst.get_device());
-        ze_command_queue_desc_t cq_desc = {ZE_STRUCTURE_TYPE_COMMAND_QUEUE_DESC, nullptr, 0, 0,
-                                           0, ZE_COMMAND_QUEUE_MODE_SYNCHRONOUS, ZE_COMMAND_QUEUE_PRIORITY_NORMAL};
-        ze_command_list_handle_t cl;
-        ze_result_t r = zeCommandListCreateImmediate(ze_ctx, ze_dev, &cq_desc, &cl);
-        if (r == ZE_RESULT_SUCCESS) {
-            r = zeCommandListAppendMemoryCopy(cl, ptr_dst, ptr_src, size, nullptr, 0, nullptr);
-            zeCommandListDestroy(cl);
+    if (g_ggml_sycl_dev2dev_memcpy == DEV2DEV_MEMCPY_L0) {
+        // Use Level Zero direct copy for dGPU-to-dGPU transfers.
+        const bool l0_copy_supported =
+            ggml_sycl_is_l0_discrete_gpu(device_dst) && ggml_sycl_is_l0_discrete_gpu(device_src);
+        if (g_ggml_sycl_enable_level_zero && l0_copy_supported) {
+            auto ze_ctx = sycl::get_native<sycl::backend::ext_oneapi_level_zero>(q_dst.get_context());
+            auto ze_dev = sycl::get_native<sycl::backend::ext_oneapi_level_zero>(q_dst.get_device());
+            ze_command_queue_desc_t cq_desc = {ZE_STRUCTURE_TYPE_COMMAND_QUEUE_DESC, nullptr, 0, 0,
+                                            0, ZE_COMMAND_QUEUE_MODE_SYNCHRONOUS, ZE_COMMAND_QUEUE_PRIORITY_NORMAL};
+            ze_command_list_handle_t cl;
+            ze_result_t r = zeCommandListCreateImmediate(ze_ctx, ze_dev, &cq_desc, &cl);
             if (r == ZE_RESULT_SUCCESS) {
-                return;
+                GGML_SYCL_DEBUG("[SYCL] dev2dev memcpy by L0\n");
+                r = zeCommandListAppendMemoryCopy(cl, ptr_dst, ptr_src, size, nullptr, 0, nullptr);
+                zeCommandListDestroy(cl);
+                if (r == ZE_RESULT_SUCCESS) {
+                    return;
+                }
             }
         }
     }
 #endif
+
+    if (g_ggml_sycl_dev2dev_memcpy == DEV2DEV_MEMCPY_SYCL) {
+        if (q_dst.get_device().ext_oneapi_can_access_peer(q_src.get_device(),
+                                                          sycl::ext::oneapi::peer_access::access_supported)) {
+            GGML_SYCL_DEBUG("[SYCL] dev2dev memcpy by SYCL\n");
+            SYCL_CHECK(CHECK_TRY_ERROR(q_dst.memcpy(ptr_dst, ptr_src, size).wait()));
+            return;
+        }
+    }
+
     // Host-staged copy
+    GGML_SYCL_DEBUG("[SYCL] dev2dev memcpy by host forward\n");
     char *host_buf = (char *)malloc(size);
     q_src.memcpy(host_buf, (const char *)ptr_src, size).wait();
     q_dst.memcpy((char *)ptr_dst, host_buf, size).wait();