Debugging with Intel® Distribution for GDB* on Linux* OS Host

Tutorial

  • 2022.2
  • 04/11/2022
  • Public Content
Contents

Multi-Target

The multi-target feature enables debugging of multiple different targets in a single debugging session.
With this feature, you can define breakpoints inside and outside the kernel to debug the host portion of the program. For example, define two breakpoints and run the target as follows:
  1. break 56
    Expected output:
    Breakpoint 1 at 0x405800: file /path/to/array-transform.cpp, line 56.
  2. break 83
    Expected output:
    Breakpoint 2 at 0x403e13: file /path/to/array-transform.cpp, line 83.
  3. run gpu
    Expected output:
    [...]
[Switching to Thread 1.1073741824 lane 0]

Thread 2.1 hit Breakpoint 1, with SIMD lanes [0-7], main::$_1::operator()[...]
  at array-transform.cpp:56
56          int element = in[index];  // breakpoint-here
Now you are inside the kernel (in this case, the kernel is running on the GPU). The context is Thread 2.1, lane 0.
Disable the breakpoint at line 56 and continue:
disable 1
continue
Expected output:
Continuing.
[Switching to Thread 0x7ffff7fd9780 (LWP 19604)]


Thread 1.1 "array-transform" hit Breakpoint 2, main (...)
  at /path/to/array-transform.cpp:83
83    cout << "success; result is correct.\n";
Try executing
print input
 and
print output
 as follows:
  • print input[6]
    Expected output:
    $1 = 106
  • print output[6]
    Expected output:
    $2 = 206
This time the stop event is received from the host. The context is automatically switched to Thread 1.1. You can investigate the host-side values as shown above.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.