version check against PyTorch's CUDA version

setup.py

@@ -54,6 +54,9 @@ def write_version_file():
     with open(version_path, 'w') as f:
         f.write("__version__ = '{}'\n".format(version))
         f.write("git_version = {}\n".format(repr(sha)))
+        f.write("from torchvision import _C\n")
+        f.write("if hasattr(_C, 'CUDA_VERSION'):\n")
+        f.write("    cuda = _C.CUDA_VERSION\n")
 
 
 write_version_file()

torchvision/__init__.py

@@ -33,3 +33,31 @@ def get_image_backend():
     Gets the name of the package used to load images
     """
     return _image_backend
+
+
+def _check_cuda_matches():
+    """
+    Make sure that CUDA versions match between the pytorch install and torchvision install
+    """
+    import torch
+    from torchvision import _C
+    if hasattr(_C, "CUDA_VERSION") and torch.version.cuda is not None:
+        tv_version = str(_C.CUDA_VERSION)
+        if int(tv_version) < 10000:
+            tv_major = int(tv_version[0])
+            tv_minor = int(tv_version[2])
+        else:
+            tv_major = int(tv_version[0:2])
+            tv_minor = int(tv_version[3])
+        t_version = torch.version.cuda
+        t_version = t_version.split('.')
+        t_major = int(t_version[0])
+        t_minor = int(t_version[1])
+        if t_major != tv_major or t_minor != tv_minor:
+            raise RuntimeError("Detected that PyTorch and torchvision were compiled with different CUDA versions. "
+                               "PyTorch has CUDA Version={}.{} and torchvision has CUDA Version={}.{}. "
+                               "Please reinstall the torchvision that matches your PyTorch install."
+                               .format(t_major, t_minor, tv_major, tv_minor))
+
+
+_check_cuda_matches()

torchvision/csrc/vision.cpp

@@ -2,10 +2,17 @@
 #include "ROIPool.h"
 #include "nms.h"
 
+#ifdef WITH_CUDA
+#include <cuda.h>
+#endif
+
 PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
   m.def("nms", &nms, "non-maximum suppression");
   m.def("roi_align_forward", &ROIAlign_forward, "ROIAlign_forward");
   m.def("roi_align_backward", &ROIAlign_backward, "ROIAlign_backward");
   m.def("roi_pool_forward", &ROIPool_forward, "ROIPool_forward");
   m.def("roi_pool_backward", &ROIPool_backward, "ROIPool_backward");
+#ifdef WITH_CUDA
+  m.attr("CUDA_VERSION") = CUDA_VERSION;
+#endif
 }