Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
Intel Debugger
==============
Debugging serial applications
-----------------------------
The intel debugger version 13.0 is available, via module intel. The
debugger works for applications compiled with C and C++ compiler and the
ifort fortran 77/90/95 compiler. The debugger provides java GUI
environment. Use [X
display](https://docs.it4i.cz/anselm-cluster-documentation/software/intel-suite/resolveuid/11e53ad0d2fd4c5187537f4baeedff33)
for running the GUI.
$ module load intel
$ idb
The debugger may run in text mode. To debug in text mode, use
$ idbc
To debug on the compute nodes, module intel must be loaded.
The GUI on compute nodes may be accessed using the same way as in [the
GUI
section](https://docs.it4i.cz/anselm-cluster-documentation/software/intel-suite/resolveuid/11e53ad0d2fd4c5187537f4baeedff33)
Example:
$ qsub -q qexp -l select=1:ncpus=16 -X -I
qsub: waiting for job 19654.srv11 to start
qsub: job 19654.srv11 ready
$ module load intel
$ module load java
$ icc -O0 -g myprog.c -o myprog.x
$ idb ./myprog.x
In this example, we allocate 1 full compute node, compile program
myprog.c with debugging options -O0 -g and run the idb debugger
interactively on the myprog.x executable. The GUI access is via X11 port
forwarding provided by the PBS workload manager.
Debugging parallel applications
-------------------------------
Intel debugger is capable of debugging multithreaded and MPI parallel
programs as well.
### Small number of MPI ranks
For debugging small number of MPI ranks, you may execute and debug each
rank in separate xterm terminal (do not forget the [X
display](https://docs.it4i.cz/anselm-cluster-documentation/software/intel-suite/resolveuid/11e53ad0d2fd4c5187537f4baeedff33)).
Using Intel MPI, this may be done in following way:
$ qsub -q qexp -l select=2:ncpus=16 -X -I
qsub: waiting for job 19654.srv11 to start
qsub: job 19655.srv11 ready
$ module load intel impi
$ mpirun -ppn 1 -hostfile $PBS_NODEFILE --enable-x xterm -e idbc ./mympiprog.x
In this example, we allocate 2 full compute node, run xterm on each node
and start idb debugger in command line mode, debugging two ranks of
mympiprog.x application. The xterm will pop up for each rank, with idb
prompt ready. The example is not limited to use of Intel MPI
### Large number of MPI ranks
Run the idb debugger from within the MPI debug option. This will cause
the debugger to bind to all ranks and provide aggregated outputs across
the ranks, pausing execution automatically just after startup. You may
then set break points and step the execution manually. Using Intel MPI:
$ qsub -q qexp -l select=2:ncpus=16 -X -I
qsub: waiting for job 19654.srv11 to start
qsub: job 19655.srv11 ready
$ module load intel impi
$ mpirun -n 32 -idb ./mympiprog.x
### Debugging multithreaded application
Run the idb debugger in GUI mode. The menu Parallel contains number of
tools for debugging multiple threads. One of the most useful tools is
the **Serialize Execution** tool, which serializes execution of
concurrent threads for easy orientation and identification of
concurrency related bugs.
Further information
-------------------
Exhaustive manual on idb features and usage is published at Intel
website,
<http://software.intel.com/sites/products/documentation/doclib/stdxe/2013/composerxe/debugger/user_guide/index.htm>