[Feature] CUDA Green Context Support (#7649)

sgl-kernel/python/sgl_kernel/spatial.py

@@ -0,0 +1,48 @@
+import torch
+from torch.cuda.streams import ExternalStream
+
+
+def create_greenctx_stream_by_value(
+    SM_a: int, SM_b: int, device_id: int = None
+) -> tuple[ExternalStream, ExternalStream]:
+    """
+    Create two streams for greenctx.
+    Args:
+        sm_A (int): The SM of stream A.
+        sm_B (int): The weight of stream B.
+        device_id (int): The device id.
+    Returns:
+        tuple[ExternalStream, ExternalStream]: The two streams.
+    """
+    if device_id is None:
+        device_id = torch.cuda.current_device()
+
+    res = torch.ops.sgl_kernel.create_greenctx_stream_by_value(SM_a, SM_b, device_id)
+
+    stream_a = ExternalStream(
+        stream_ptr=res[0], device=torch.device(f"cuda:{device_id}")
+    )
+    stream_b = ExternalStream(
+        stream_ptr=res[1], device=torch.device(f"cuda:{device_id}")
+    )
+
+    return stream_a, stream_b
+
+
+def get_sm_available(device_id: int = None) -> int:
+    """
+    Get the SMs available on the device.
+    Args:
+        device_id (int): The device id.
+    Returns:
+        int: The SMs available.
+    """
+    if device_id is None:
+        device_id = torch.cuda.current_device()
+
+    device_props = torch.cuda.get_device_properties(device_id)
+
+    # Get the number of Streaming Multiprocessors (SMs)
+    sm_count = device_props.multi_processor_count
+
+    return sm_count