pythonflaskpycuda

pyCUDA with Flask gives pycuda._driver.LogicError: cuModuleLoadDataEx


I want to run a pyCUDA code on a flask server. The file runs correctly directly using python3 but fails when the corresponding function is called using flask.

Here is the relevant code:

cudaFlask.py:

import pycuda.autoinit
import pycuda.driver as drv
import numpy

from pycuda.compiler import SourceModule

def cudaTest():
    mod = SourceModule("""
        int x = 4;
    """)

    print ("done")
    return

if __name__ == "__main__":
    cudaTest()

server.py (only the part which calls the function):

@app.route('/bundle', methods=['POST'])
def bundle_edges():
    cudaTest()
    return "success"

On running python cudaFlask.py I get the output done as expected but on starting the server and doing POST request at website/bundle I get the following error on the flask console:

pycuda._driver.LogicError: cuModuleLoadDataEx failed: invalid device context - 

on the line mod = SourceModule...

Where am I going wrong? There is a similar question out there but it has not been answered yet.


Solution

  • Solved the issue with lazy loading in flask and making the context manually (i.e. without pycuda.autoinit in PyCUDA.

    Refer this for lazy loading in flask.

    My views.py file:

    import numpy as np
    import pycuda.driver as cuda
    from pycuda.compiler import SourceModule
    
    def index():
        cuda.init()
        device = cuda.Device(0) # enter your gpu id here
        ctx = device.make_context()
    
        mod = SourceModule("""
            int x = 4;
        """)
    
        ctx.pop() # very important
    
        print ("done")
        return "success"