[GitHub] eric-haibin-lin opened a new issue #8645: gluon.utils.split_and_load(even_split=True) is much slower than even_split=False

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eric-haibin-lin opened a new issue #8645: gluon.utils.split_and_load(even_split=True) is much slower than even_split=False
URL: https://github.com/apache/incubator-mxnet/issues/8645
 
 
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   ## Description
   ```
   import mxnet as mx
   from mxnet import gluon
   import time
   ctx_list = [mx.cpu(0), mx.cpu(1)]
   label = mx.nd.ones((128,240000))
   mx.nd.waitall()
   start = time.time()
   for i in range(10):
       labels = gluon.utils.split_and_load(label, ctx_list, batch_axis=1, even_split=True)
   mx.nd.waitall()
   end = time.time()
   print(end - start)
   ```
   It takes 2.236 seconds. If `even_split` is changed to `False`, it only takes 0.68 seconds.
   
   ## Environment info (Required)
   
   Deep Learning AMI CUDA 9 Ubuntu, p2.8xlarge.
   
   ```
   What to do:
   1. Download the diagnosis script from https://raw.githubusercontent.com/apache/incubator-mxnet/master/tools/diagnose.py
   2. Run the script using `python diagnose.py` and paste its output here.
   
   ```
   
   Package used (Python/R/Scala/Julia):
   (I'm using ...)
   
   For Scala user, please provide:
   1. Java version: (`java -version`)
   2. Maven version: (`mvn -version`)
   3. Scala runtime if applicable: (`scala -version`)
   
   For R user, please provide R `sessionInfo()`:
   
   ## Build info (Required if built from source): 
   
   Compiler (gcc/clang/mingw/visual studio):
   
   MXNet commit hash: 399ac038da885ff3dce8e43bcbdf76bb62522e73
   (Paste the output of `git rev-parse HEAD` here.)
   
   Build config: 
   (Paste the content of config.mk, or the build command.)
   ```
   USE_BLAS=openblas
   ADD_CFLAGS += -I/usr/include/openblas
   USE_CUDA=1
   USE_CUDA_PATH=/usr/local/cuda
   USE_CUDNN=1
   ```
   
   ## Error Message:
   (Paste the complete error message, including stack trace.)
   
   ## Minimum reproducible example
   (If you are using your own code, please provide a short script that reproduces the error. Otherwise, please provide link to the existing example.)
   
   
   
   ## Steps to reproduce
   (Paste the commands you ran that produced the error.)
   
   1.
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   ## What have you tried to solve it?
   
   1.
   2.
   

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