metal : make the backend async (#15906)

* metal : make the backend async

ggml-ci

* cont : add comments, extend op offload, clean up

ggml-ci

* metal : fix batch size for MUL_MAT_ID

* metal : remove deprecated ggml_backend_metal_buffer_from_ptr

* metal : create only metal buffers, no wrapping of host memory

ggml-ci

* metal : restore .alloc_buffer for buffer_from_ptr_type

ggml-ci

* metal : remove broken implementation of GGML_OP_SET

ggml-ci

* metal : clean-up loose ends, ready for tests

ggml-ci

* metal : support both private and shared buffers

ggml-ci

* metal : enable private buffers + add global device queue

* metal : disable host buffer to prevent races

ggml-ci

* metal : avoid extra copy during set_tensor

ggml-ci

* metal : use separate buffer types for shread and private Metal buffers

ggml-ci

* metal : simplify synchronization logic

ggml-ci

* metal : fix build

ggml-ci

* metal : do not implement cpy_tensor

ggml-ci

* metal : separate implementations for shared and private buffers

ggml-ci

ggml/include/ggml-metal.h

@@ -43,14 +43,8 @@ GGML_BACKEND_API ggml_backend_t ggml_backend_metal_init(void);
 
 GGML_BACKEND_API bool ggml_backend_is_metal(ggml_backend_t backend);
 
-GGML_DEPRECATED(
-        GGML_BACKEND_API ggml_backend_buffer_t ggml_backend_metal_buffer_from_ptr(void * data, size_t size, size_t max_size),
-        "obsoleted by the new device interface - https://github.com/ggml-org/llama.cpp/pull/9713");
-
 GGML_BACKEND_API void ggml_backend_metal_set_abort_callback(ggml_backend_t backend, ggml_abort_callback abort_callback, void * user_data);
 
-GGML_BACKEND_API ggml_backend_buffer_type_t ggml_backend_metal_buffer_type(void);
-
 // helper to check if the device supports a specific family
 // ideally, the user code should be doing these checks
 // ref: https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf

ggml/src/ggml-metal/ggml-metal.metal

@@ -5571,38 +5571,6 @@ kernel void kernel_flash_attn_ext_vec_reduce(
 #undef DV
 }
 
-template<typename T>
-kernel void kernel_set(
-    constant ggml_metal_kargs_set & args,
-    device  const char * src0,
-    device  const char * src1,
-    device        char * dst,
-    uint3   tgpig[[threadgroup_position_in_grid]],
-    ushort3 tpitg[[thread_position_in_threadgroup]],
-    ushort3   ntg[[threads_per_threadgroup]]) {
-    const int i13 = tgpig[2];
-    const int i12 = tgpig[1];
-    const int i11 = tgpig[0];
-
-    const int64_t n = i13*args.ne12*args.ne11*args.ne10 + i12*args.ne11*args.ne10 + i11*args.ne10;
-
-    const int64_t i3 = n / (args.ne12*args.ne11*args.ne10);
-    const int64_t i2 = (n - i3*args.ne12*args.ne11*args.ne10) / (args.ne11*args.ne10);
-    const int64_t i1 = (n - i3*args.ne12*args.ne11*args.ne10 - i2*args.ne11*args.ne10) / args.ne10;
-
-    device T * dst_data = (device T *) (dst + i3*args.nb3 + i2*args.nb2 + i1*args.nb1 + args.offs);
-
-    for (int64_t i10 = tpitg.x; i10 < args.ne10; i10 += ntg.x) {
-        device const T * src = (device T *) (src1 + i13*args.nb13 + i12*args.nb12 + i11*args.nb11 + i10*args.nb10);
-        dst_data[i10] = (T) src[0];
-    }
-}
-
-typedef decltype(kernel_set<float>) kernel_set_t;
-
-template [[host_name("kernel_set_f32")]] kernel kernel_set_t kernel_set<float>;
-template [[host_name("kernel_set_i32")]] kernel kernel_set_t kernel_set<int32_t>;
-
 template<typename T0, typename T1>
 kernel void kernel_cpy(
         constant ggml_metal_kargs_cpy & args,