Initial release

engine/ggml/src/ggml-cuda/allreduce.cuh

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "common.cuh"
+#include "ggml-backend-impl.h"
+
+#include <cstddef>
+
+// Opaque pipeline context -- owns all pinned buffers, streams, and events.
+struct ggml_cuda_ar_pipeline;
+
+// Allocate a pipeline for n_devices GPUs.
+// devices[] holds the CUDA device IDs in rank order.
+// Returns nullptr on allocation failure.
+ggml_cuda_ar_pipeline * ggml_cuda_ar_pipeline_init(
+    const int * devices, size_t n_devices);
+
+// Release all resources owned by the pipeline.
+void ggml_cuda_ar_pipeline_free(ggml_cuda_ar_pipeline * pipeline);
+
+// Execute an in-place AllReduce (sum) across tensors[0..n_devices-1].
+// tensors[i] must live on the device managed by backends[i] and be
+// contiguous F32, F16, or BF16.
+// Preconditions are checked by the CUDA comm dispatcher before calling this.
+// Returns true once the reduction work has been enqueued successfully.
+bool ggml_cuda_ar_allreduce(
+    ggml_cuda_ar_pipeline * pipeline,
+    ggml_backend_t        * backends,
+    ggml_tensor           ** tensors);
+