fix grad_output uncontiguous (#737)

* fix grad_output uncontiguous * add comments for uncontiguous
2020-12-21 17:21:20 +08:00 · 2020-12-21 17:21:20 +08:00 · ae982b2806
parent dedd79940e
commit ae982b2806
1 changed files with 2 additions and 1 deletions
--- a/mmcv/ops/roi_align.py
+++ b/mmcv/ops/roi_align.py
@ -94,7 +94,8 @@ class RoIAlignFunction(Function):
    def backward(ctx, grad_output):
        rois, argmax_y, argmax_x = ctx.saved_tensors
        grad_input = grad_output.new_zeros(ctx.input_shape)
-
+        # complex head architecture may cause grad_output uncontiguous.
+        grad_output = grad_output.contiguous()
        ext_module.roi_align_backward(
            grad_output,
            rois,