Delays in open nvidia device file

Hi !

Trying to use CUDA, I have observed some delays in cuInit performing.

By the deep exploration, I have found that the reason is in very slow opening

of nvidia device files.

For example, the operator

int fd = open( “/dev/nvidia0”, O_RDWR);

is performing in 1,5 seconds for Device 0: “Tesla M2050”:

$ ./openTest

open time = 1.5190  secs.

The same thing is occurred for Device 0: “Tesla C1060”,

but the time is slightly less:

$ ./openTest

open time = 0.8532  secs.

My question is what it is and how to fix it ?

I am using Linux CentOS release 5.4 (Final) with

2.6.18-164.el5 kernel.



This is a known problem and will be fixed in the next CUDA release.

For the moment, you can work around it by running nvidia-smi in the background:
nvidia-smi --loop-continuously --interval=60 --filename=/var/log/nvidia-smi.log &