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I'm trying to train a neural net on a GPU using Keras and am getting a "Resource exhausted: OOM when allocating tensor" error. The specific tensor it's trying to allocate isn't very big, so I assume some previous tensor consumed almost all the VRAM. The error message comes with a hint that suggests this:

Hint: If you want to see a list of allocated tensors when OOM happens, add report_tensor_allocations_upon_oom to RunOptions for current allocation info.

That sounds good, but how do I do it? RunOptions appears to be a Tensorflow thing, and what little documentation I can find for it associates it with a "session". I'm using Keras, so Tensorflow is hidden under a layer of abstraction and its sessions under another layer below that.

How do I dig underneath everything to set this option in such a way that it will take effect?

dspeyer
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4 Answers4

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TF1 solution:

Its not as hard as it seems, what you need to know is that according to the documentation, the **kwargs parameter passed to model.compile will be passed to session.run

So you can do something like:

import tensorflow as tf
run_opts = tf.RunOptions(report_tensor_allocations_upon_oom = True)

model.compile(loss = "...", optimizer = "...", metrics = "..", options = run_opts)

And it should be passed directly each time session.run is called.

TF2:

The solution above works only for tf1. For tf2, unfortunately, it appears there is no easy solution yet.

Manuel Popp
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Dr. Snoopy
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Currently, it is not possible to add the options to model.compile. See: https://github.com/tensorflow/tensorflow/issues/19911

Richard
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    While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – Enea Dume Aug 15 '18 at 15:03
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OOM means out of memory. May be it is using more memory at that time. Decrease batch_size significantly. I set to 16, then it worked fine

naam
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  • Whether that will work, and what batch size is appropriate, will depend entirely on the model in question, as well as the dataset. If one is attempting to debug a memory issue that doesn't depend on batch size, this doesn't help at all. – Adam Azarchs Feb 24 '21 at 23:37
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Got the same error, but only in case, the training dataset was about the same as my GPU memory. For example, with 4 Gb video card memory I can train the model with the ~3,5 GB dataset. The workaround for me was to create the data_generator custom function, with yield, indices, and lookback. The other way I was suggested was to start learning true tensorflow framework and with tf.Session (example).

ouflak
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