Re: libgompd output test

[Jakub Jelinek <jakub@redhat.com>]

On Wed, Jun 29, 2022 at 06:45:51AM +0200, Mohamed Atef wrote:
> for this test case,
> 
> 1.#include <stdio.h>
> 2.#include <omp.h>
> 3.int
> 4.main()
> 5.{
> 6.  omp_set_num_threads (5);
> 7.  #pragma omp parallel
> 8.    {
> 9.      int th = omp_get_thread_num ();
> 10.      printf ("i am thread %d\n", th);
> 11.    }
> 12.  return 0;
> 13.}

You can also use OMP_DISPLAY_ENV=verbose in the environment
to see how it is printed by the runtime.

> Reading symbols from a.out...
> OMPD GDB support loaded
> Run 'ompd init' to start debugging
> (gdb) ompd init
> Temporary breakpoint 1 at 0x40115a: file pro.c, line 6.
> [Thread debugging using libthread_db enabled]
> Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
> 
> Temporary breakpoint 1, main () at pro.c:6
> 6  omp_set_num_threads (5);
> Loaded OMPD lib successfully!

Is the GDB OMPD patch available somewhere?

> (gdb) b 10
> Breakpoint 2 at 0x401198: file pro.c, line 10.
> (gdb) c
> Continuing.
> [New Thread 0x7ffff7d45700 (LWP 116224)]
> [New Thread 0x7ffff7544700 (LWP 116225)]
> [New Thread 0x7ffff6d43700 (LWP 116226)]
> [Switching to Thread 0x7ffff7d45700 (LWP 116224)]
> 
> Thread 2 "a.out" hit Breakpoint -14, gomp_thread_start
> (xdata=0x7fffffffd950) at ../../../gcc/libgomp/config/linux/sem.h:46
> 46  *sem = value * SEM_INC;
> [New Thread 0x7ffff6542700 (LWP 116227)]
> [Switching to Thread 0x7ffff7544700 (LWP 116225)]
> 
> Thread 3 "a.out" hit Breakpoint -14, gomp_thread_start
> (xdata=0x7fffffffd9d0) at ../../../gcc/libgomp/config/linux/sem.h:46
> 46  *sem = value * SEM_INC;
> [Switching to Thread 0x7ffff6d43700 (LWP 116226)]
> 
> Thread 4 "a.out" hit Breakpoint -14, gomp_thread_start
> (xdata=0x7fffffffda50) at ../../../gcc/libgomp/config/linux/sem.h:46
> 46  *sem = value * SEM_INC;
> [Switching to Thread 0x7ffff6542700 (LWP 116227)]
> 
> Thread 5 "a.out" hit Breakpoint -14, gomp_thread_start
> (xdata=0x7fffffffdad0) at ../../../gcc/libgomp/config/linux/sem.h:46
> 46  *sem = value * SEM_INC;
> 
> Thread 5 "a.out" hit Breakpoint 2, main._omp_fn.0 () at pro.c:10
> 10    printf ("i am thread %d\n", th);
> (gdb) bt
> #0  main._omp_fn.0 () at pro.c:10
> #1  0x00007ffff7f9dd8e in gomp_thread_start (xdata=<optimized out>) at
> ../../../gcc/libgomp/team.c:131
> #2  0x00007ffff7f48609 in start_thread (arg=<optimized out>) at
> pthread_create.c:477
> #3  0x00007ffff7e6d133 in clone () at
> ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
> (gdb) ompd icv
> Initialized ICV map successfully for checking OMP API values.
> ICV                                Name Scope                 Value
> ===============================================================
> cancel var                      address_space             0
> max task priority var           address_space          0
> stack size var                  address_space             0
> debug var                       address_space              0
> OMP_DEBUG                address_space              enabled
> display affinity var            address_space              0
> affinity format var             address_space              level %L thread
> %i affinity %A

This ought to be IMHO printed as a string literal, so "level %L thread %i affinity %A"

> affinity format len var         address_space              0
> wait policy var                 address_space              4294967295
> num teams var                   address_space              0
> teams thread limit var          address_space              0
> spin count var                  address_space              300000
> num proc var                    address_space              8
> throttled spin count var        address_space              100
> managed threads var             address_space              5

And also, it would be nice if it was clear which ICVs are GCC implementation
specific and which are standard (the spin count vars are non-standard).
Also, the names of ICVs in the standard are with hyphens, so perhaps print
cancel-var, max-task-priority-var etc.?

	Jakub