How to set specific gpu in tensorflow?

Question

I want to specify the gpu to run my process. And I set it as follows:

import tensorflow as tf
with tf.device('/gpu:0'):
    a = tf.constant(3.0)
with tf.Session() as sess:
    while True:
        print sess.run(a)

However it still allocate memory in both my two gpus.

|    0      7479    C   python                         5437MiB 
|    1      7479    C   python                         5437MiB 

Answer 1

There are 3 ways to achieve this:

1. Using CUDA_VISIBLE_DEVICES environment variable. by setting environment variable CUDA_VISIBLE_DEVICES="1" makes only device 1 visible and by setting CUDA_VISIBLE_DEVICES="0,1" makes devices 0 and 1 visible. You can do this in python by having a line os.environ["CUDA_VISIBLE_DEVICES"]="0,1" after importing os package.

2. Using with tf.device('/gpu:2') and creating the graph. Then it will use GPU device 2 to run.

3. Using config = tf.ConfigProto(device_count = {'GPU': 1}) and then sess = tf.Session(config=config). This will use GPU device 1.