Caffe multi CPU build | 易学教程

问题

I'm trying to build Caffe on Ubuntu 14.04 x64 in VirtualBox with openblas in CPU_ONLY mode.(Enviroment install script , Makefile.config )

Also I'm not compiling OpenBlas, but install it via apt-get like sudo apt-get -y install libopenblas-dev, can it be reason of the problem?

After I set any of this variables, there is no speed improvement and in htop I see only one CPU utilisation.

export OPENBLAS_NUM_THREADS=4
export GOTO_NUM_THREADS=4
export OMP_NUM_THREADS=4

How to check if Caffe use several threads / CPUs?

UPDATE:

I tried caffe binary on MNIST example and it utilise 400% of CPU.

1 thread

I0520 15:58:09.749832 12424 caffe.cpp:178] Use CPU.
...
I0520 16:06:14.553506 12424 caffe.cpp:222] Optimization Done.
~8 min

4 threads

I0520 16:06:44.634735 12446 caffe.cpp:178] Use CPU.
...
I0520 16:13:15.904394 12446 caffe.cpp:222] Optimization Done.
~6.5 min

ps -T -p <PID> gives me:

export OPENBLAS_NUM_THREADS=1 6 threads

export OPENBLAS_NUM_THREADS=4 9 threads

Seems openblas works, but it depends on network architecture?

Also seems Caffe also use BLAS for conv layers.

回答1:

I'm using the intel branch on CentOS 7.3 and able to see 2500% CPU usage on my Broadwell when training caffenet example. The following is the steps I used to build the tools:

git clone https://github.com/BVLC/caffe.git caffe_intel
cd caffe_intel
git branch -r
git checkout intel
cp Makefile.config.example Makefile.config
  # mkl will be automatically download once make is run
  # Edit Makefile.config in the following lines
  PYTHON_LIB := /usr/lib64
  LIBRARY_DIRS := $(PYTHON_LIB) /usr/local/lib /usr/lib64 /usr/lib   
yum install cmake # will be used to build mkl as a sub-routine of make
make -j32 all
make pycaffe
make distribute
cd distribute/lib
ln -s ../../external/mkldnn/install/lib/libmkldnn.so .

And put caffe_intel/distribute/bin in $PATH, caffe_intel/distribute/lib in $LD_LIBRARY_PATH. Also, enable mkl library by adding the following line at the beginning of prototxt file(s)

engine: "MKL2017"

来源：https://stackoverflow.com/questions/37327064/caffe-multi-cpu-build

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multithreading

build

multiprocessing

caffe