[pocl-devel] Debug symbols for kernel

[Timo B. <tim...@gm...>]

Hi,

I am observing a crash with one of my OpenCL kernels on POCL in double
precison (single precision works fine). I don't observe this crash on other
OpenCL implementations and printf debugging does not really show what is
going on.

I am running my kernels through PyOpenCL. I tried to debug with gdb --args
python test_p1.py.
But while POCL debug symbols are shown, they are not shown for the kernel.
The only message I get is that the crash is in
_pocl_launcher_evaluate_regular. The full gdb output is shown below up to
the first function that has debug symbols available.

Any hint would be great.

Best wishes

Timo
-----------------------------------

Starting program: /home/betcke/.conda/envs/opencl/bin/python ./test_p1.py
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Missing separate debuginfo for
/home/betcke/.conda/envs/opencl/lib/python3.6/site-packages/numpy/../../../libiomp5.so
Missing separate debuginfo for /lib64/libOpenCL.so.1
Try: dnf --enablerepo='*debug*' install
/usr/lib/debug/.build-id/18/de8b5046adcfe0be9627f9cdab1812fe715d89.debug
[New Thread 0x7fffd6dca700 (LWP 11143)]
[New Thread 0x7fffd65c9700 (LWP 11144)]
[New Thread 0x7fffd5dc8700 (LWP 11145)]
[New Thread 0x7fffd55c7700 (LWP 11146)]
[Thread 0x7fffd55c7700 (LWP 11146) exited]
[Thread 0x7fffd5dc8700 (LWP 11145) exited]
[Thread 0x7fffd65c9700 (LWP 11144) exited]
[Thread 0x7fffd6dca700 (LWP 11143) exited]
X server found. dri2 connection failed!
[New Thread 0x7fffd55c7700 (LWP 11147)]
Default device: pthread-Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz
Detaching after fork from child process 11148.
Detaching after fork from child process 11150.

Thread 6 "python" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffd55c7700 (LWP 11147)]
0x00007fffae8f6865 in _pocl_launcher_evaluate_regular () from
/home/betcke/.cache/pocl/kcache/GG/BJMJJGGNAPAMOJGKFMNAAIEDJNENJNLGAPNEO/evaluate_regular/0-0-0/evaluate_regular.so
(gdb) up
#1  0x00007fffae8f6cc9 in _pocl_launcher_evaluate_regular_workgroup () from
/home/betcke/.cache/pocl/kcache/GG/BJMJJGGNAPAMOJGKFMNAAIEDJNENJNLGAPNEO/evaluate_regular/0-0-0/evaluate_regular.so
(gdb) up
#2  0x00007fffd6f8694d in work_group_scheduler (thread_data=0xc4d2c0,
k=0x7fffc0001a80) at
/usr/src/debug/pocl-1.1-2.fc28.x86_64/lib/CL/devices/pthread/pthread_scheduler.c:407
407           k->workgroup (arguments, &pc);
(gdb)

----------------------------------
-- 
Dr Timo Betcke
Reader in Mathematics
University College London
Department of Mathematics
E-Mail: t.b...@uc...
Tel.: +44 (0) 20-3108-4068
Fax.: +44 (0) 20-7383-5519