#Unable to use PyTorch from Mojo

1 messages · Page 1 of 1 (latest)

rocky sigil
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I just wanted to try Pytorch and created a project using nightly build.
I then installed PyTorch using: magic add "pytorch".

This is the code I tried:
`from python import Python

fn main() raises:
torch = Python.import_module("torch")
x = torch.tensor([1, 2, 3])
print(x)`

It resulted in the following error:
Unhandled exception caught during execution: libmkl_intel_lp64.so.2: cannot open shared object file: No such file or directory mojo: error: execution exited with a non-zero result: 1

I can see "libmkl_intel_lp64.so.2" in the .magic\envs\default\lib folder so I do not understand what the problem is.

feral zodiacBOT
#

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stray sparrow
rocky sigil
#

How do I do that?

stray sparrow
rocky sigil
#

This the content of momproject.toml:

`[project]
channels = ["conda-forge", "https://conda.modular.com/max-nightly"]
description = "Add a short description here"
name = "mojo_by_example-nightly"
platforms = ["linux-64"]
version = "0.1.0"

[tasks]

[dependencies]
max = ">=25.1.0.dev2024121305,<26"
numpy = ">=1.26.4,<2"
jax = ">=0.4.35,<0.5"
pydicom = ">=3.0.1,<4"
torchvision = ">=0.20.1,<0.21"
pytorch = ">=2.5.1,<3"`

stray sparrow
#

And you are inside of the magic environment when compiling and running?

rocky sigil
#

Yes, I made sure to double-check.

stray sparrow
#

One second, let me run it locally.

#

Ok, so I have oneAPI installed and it picked it up as my system BLAS.

#

Let me try that in a container.

#

I can reproduce it, so it's a Mojo issue.

#

@rocky sigil It's probably easiest to add the mkl package to get the dependency while we sort out what exactly pytorch did, since it seems like this is their fault.

rocky sigil
#

Thanks. I will read through that page.

stray sparrow
#

As a note, MKL is quite a bit faster than OpenBLAS, which is what pytorch and numpy used before.

#

So this is an upgrade, just one that appears to have had some consequences for the ecosystem.

rocky sigil
#

Is there any performance-related issue given that I am on an AMD system?

feral zodiacBOT
stray sparrow
rocky sigil
#

It's an AMD Ryzen 9 4900HS.

stray sparrow
#

MKL's alleged "crippling of AMD CPUs" was actually around servers that didn't support AVX-512, and MKL only has AVX-512 and scalar fallbacks, but Zen 4 and 5 support AVX-512 and see the same perf as Intel CPUs.

#

That one is probably going to be a bit worse than openblas, since iirc it has AVX2.

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But, this is not going to be a gigantic difference for most workloads unless you are doing AI on the CPU.

rocky sigil
#

Ah, that;'s good to know.
One last question, can I add the dependency for openblas using magic and how do I do it? I am still figuring my way around mojo.

green otterBOT
#

Congrats @rocky sigil, you just advanced to level 2!

stray sparrow
#

The basic syntax is in that docs page I sent.

#

How exactly pixi, the underlying tool for magic, decided to translate that to toml I don't know, you may have to play around a bit.

rocky sigil
#

OK, thanks. I will have a play around now.

frosty locust
#

@rocky sigil I have the same issue... did you find out how to add mkl using magic?

frosty locust
#

It seems that I could solve it by setting LD_LIBRARY_PATH to .magic/envs/default/lib - export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:.magic/envs/default/lib

rocky sigil
#

That's great.
I solved the PyTorch issue by adding it to the channels array in mojoproject.toml like so:
channels = ["pytorch", "conda-forge", "https://conda.modular.com/max"]