Check dtype of input tensors is correct#23
Check dtype of input tensors is correct#23acarapetis wants to merge 3 commits intofacebookresearch:mainfrom
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It looks like this was meant to be NotImplementedError, but that's not really appropriate anyway, since this isn't an abstract method. Since any other dtype is really just a bad input, a ValueError seems appropriate.
If a 16-bit float tensor on the CPU was passed as the input to quantize_blockwise or the output buffer for dequantize_blockwise, the code was previously passing its pointer to the c[de]quantize_blockwise_cpu_fp32 method, silently casting it to a 32-bit float* and resulting in segfaults. A similar issue occurs if the absmax/code arguments to dequantize_blockwise are float16s, resulting in illegal memory accesses on the GPU. This commit adds some simple dtype guards to ensure the tensors have the expected type before passing them to the C extension.
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Thanks for this PR! I am currently preparing a major overhaul of these algorithms and interfaces. I have to check how to best integrate this PR. |
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If a 16-bit float tensor on the CPU was passed as the input to quantize_blockwise or the output buffer for dequantize_blockwise, the code was previously passing its address to the
c[de]quantize_blockwise_cpu_fp32 method, silently casting it to a 32-bit float* and resulting in segfaults.A similar issue occurs if the absmax/code arguments to
dequantize_blockwiseare (somehow) 16-bit, resulting in illegal memory accesses on the GPU.It took me a little while to track down the causes because of the cryptic errors; so I figured it was worth suggesting these changes. I've only been using the blockwise methods, so it's possible there are similar issues in other parts of the code - might be worth checking :)
This PR also includes a couple unrelated typo fixes.
Thanks for your work on this library, it's nice to squeeze the most I can out of my paltry GPU memory :)