CUDA + Fork = ?

Accelerated Computing CUDA CUDA Programming and Performance
1

Suppose you have a Linux process with a CUDA context it is presently using. Then you fork() that process. What happens?

Thanks,
Andreas

2

The context is not going to transparently move or be copied, if that’s what you’re after.

3

I’m after any kind of defined behavior, really. :)

Possible answers:

    [*] The context sticks with the parent, all access to the context in the child is invalid.

    [*] Both processes get to poke around in the same context.

    [*] Your program will crash and burn, because libcuda maintains too much state for its own good.

I’d rather not find out by trial-and-error, that’s all.

4

This is how it worked back in the CUDA 0.8 days, at least according to some people who played around with trial and error. I have no idea if the behavior has changed.

5

Uh-oh, now I need to play with it. I was assuming the parent was fine but the child would not have a context.

6

I didn’t mean to make more work for you, Tim :)

Here is the forum thread I was thinking of. I guess I slightly overexaggerated its age, it was posted only 11 months ago.

http://forums.nvidia.com/index.php?showtop…318&hl=fork