Nsight (cuda-gdb) on Macbook Pro

Hi all,

I’m trying to debug a Cuda application on a Retina Macbook Pro with a GT750M. I’m compiling all cuda code with -g -G as required by cuda-gdb. However I’ve not been able to get cuda-gdb to stop at a breakpoint in device code. What I get is the following:

Error in re-setting breakpoint 2: Cannot access memory at address 0x47e0
Error in re-setting breakpoint 3: Cannot access memory at address 0x4690
Error in re-setting breakpoint 4: Cannot access memory at address 0x4690
Error in re-setting breakpoint 5: Cannot access memory at address 0x4690

Each line corresponds to a device code breakpoint. Host code breakpoints work fine. Has anyone come up against this? I can’t seem to find anything on Google. I’m wondering if this has got something to do with Optimus switching on laptops? I’ve tried turning off the switching feature to no avail.

Just in case, I tried Nsight with the exact same settings and build configuration on a machine running a GTX960 and it worked as expected.

Any help would be much appreciated!

First set a breakpoint in your main() routine (host code). Then run till you hit that breakpoint. Then try to set a breakpoint in device code. It’s also necessary for the kernel not to crash before it hits your breakpoint (you have to have a successful launch up to that point) so try putting your first device breakpoint at the first line of code in your kernel.