Segmentation fault

[AndrewBoWen666]

OS: Ubuntu 18.04

When I run test_opencl, it showed the "segmentation fault". Any idea?

[jjd06]

Not without a bit more information! Have you tried debugging?

[AndrewBoWen666]

Sorry I forgot to attach error messages. The following messages was obtained when i use "dmesg".

And here is an exception when I trying to display my devices in "step_world_v3_opencl".

This issue is quite wired since it seems the exception indicates that I don't have any device, but as you see I do have a device when I run test_opencl. (I am not sure is this excpetion means I don't have device.)

[adityarajagopal]

With regards to the exception you are getting when you are running step_world_v3_lambda, it's saying that your vector size is 1 (suggesting it has the 1 platform that has been found), but you're accessing out of range (as it displays "Choosing platform 1"). So this exception should be fixed if you choose platform 0 instead of 1.

[AndrewBoWen666]

Ahhhh... Thanks a lot. I didn't even notice the platform index, but the segmentation fault comes again as test_opencl. Do you have any idea on this?
.

[tnugent97]

Could you attach the output of your program when run on gdb? (in gdb, type backtrace after the program is run to get a breakdown of where exactly the seg fault occurs)

[JinYeeNg]

For bin/test_opencl, this is the message showed when I use gdb to debug it. Let me know if the information in the image is not enough.

[tnugent97]

Can you change the makefile to add the flag -g? This adds debug symbols so gdb can tell us where the seg fault occurs.
Do you definitely have the correct version of openCL installed?
If you get really stuck with openCL on your machine, I would recommend using AWS. It's super easy to use!

Edit: I've also done a search for your GPU (https://www.geforce.com/hardware/notebook-gpus/geforce-gt-625m/specifications) and this seems to say only OpenCL 1.1 is supported. Not sure if this is an issue.

[JinYeeNg]

Ok, thank you. My GPU which supports only OpenCL 1.1 seems to be the source of my issue.