[theano-users] Theano profiling question

[Haining Yu]

Hello,

I have a question about how to read theano profiling results. I am running
a RNN model, where the gradient is calculated via theano.scan. When I
profile the code, I can see that the bulk of time is spent on theano.scan.
Moreover I notice that the type of call is Py rather than C.

My questions are:
1. does <type> = Py imply that the code is running as python code?
2. does this also imply the code is executed on CPU (instead of GPU)?

Thanks,
Haining

Below is results from profiling:

Class
---
<% time> <sum %> <apply time> <time per call> <type> <#call> <#apply>
<Class name>
99.3% 99.3% 624.260s 1.90e-01s Py 3284 2
theano.scan_module.scan_op.Scan
0.2% 99.5% 1.237s 1.57e-05s C 78816 48
theano.sandbox.cuda.basic_ops.GpuAlloc
0.2% 99.7% 1.028s 2.02e-05s C 50902 31
theano.sandbox.cuda.basic_ops.GpuElemwise
0.1% 99.7% 0.394s 1.64e-06s C 239732 146
...

Ops
---
<% time> <sum %> <apply time> <time per call> <type> <#call> <#apply> <Op
name>
87.3% 87.3% 548.530s 3.34e-01s Py 1642 1
forall_inplace,gpu,grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn}
12.0% 99.3% 75.730s 4.61e-02s Py 1642 1
forall_inplace,gpu,scan_fn&scan_fn&scan_fn&scan_fn}
0.2% 99.5% 1.237s 1.57e-05s C 78816 48

...

[Pascal Lamblin]

Hi,
<type> = Py shows that the Python interface is used for that Op. However,
in Scan's case, that Python implementation uses Cython, so most of the
performance of C should be there.
Python code can also execute the computation on the GPU. In that case, you
can see in the Op list that the scan Ops print as "forall_inplace,gpu,...",
which confirm they are actually running on the GPU.

Post by Haining Yu
Hello,
I have a question about how to read theano profiling results. I am running
a RNN model, where the gradient is calculated via theano.scan. When I
profile the code, I can see that the bulk of time is spent on theano.scan.
Moreover I notice that the type of call is Py rather than C.
1. does <type> = Py imply that the code is running as python code?
2. does this also imply the code is executed on CPU (instead of GPU)?
Thanks,
Haining
Class
---
<% time> <sum %> <apply time> <time per call> <type> <#call> <#apply>
<Class name>
99.3% 99.3% 624.260s 1.90e-01s Py 3284 2
theano.scan_module.scan_op.Scan
0.2% 99.5% 1.237s 1.57e-05s C 78816 48
theano.sandbox.cuda.basic_ops.GpuAlloc
0.2% 99.7% 1.028s 2.02e-05s C 50902 31
theano.sandbox.cuda.basic_ops.GpuElemwise
0.1% 99.7% 0.394s 1.64e-06s C 239732 146
...
Ops
---
<% time> <sum %> <apply time> <time per call> <type> <#call> <#apply> <Op
name>
87.3% 87.3% 548.530s 3.34e-01s Py 1642 1
forall_inplace,gpu,grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn&grad_of_scan_fn}
12.0% 99.3% 75.730s 4.61e-02s Py 1642 1
forall_inplace,gpu,scan_fn&scan_fn&scan_fn&scan_fn}
0.2% 99.5% 1.237s 1.57e-05s C 78816 48
...

[Haining Yu]

Thank you for the response. It helps a lot.