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libgomp and OMP_NUM_THREADS
- From: Walter Szeliga <Walter dot Szeliga at Colorado dot edu>
- To: gcc at gcc dot gnu dot org
- Date: Thu, 19 Jan 2006 16:35:17 -0700
- Subject: libgomp and OMP_NUM_THREADS
Hello,
It appears that although the most recent svn update (Revision
109975) of gcc compiles apparently fine, simple OpenMP programs will
only operate when OMP_NUM_THREADS=1. I am compiling and running gcc
on a Dual CPU G5 PowerPC running OS X 10.4.4. If I compile
omp_hello.c from testsuite/libgomp.c with
gcc -fopenmp omp_hello.c -o omp_hello -lgomp
then the program reports that 1 thread is created. If I then set
OMP_NUM_THREADS=2, omp_hello hangs. If one runs recomplies this
program, runs it in gdb and Ctrl-C's it when it hangs, here is the
backtrace generated
#0 0x900c48fc in sem_wait ()
#1 0x00020c24 in gomp_sem_wait (sem=0x222c4) at ../../../gomp/
libgomp/config/posix/sem.c:44
#2 0x00020d68 in gomp_barrier_wait_end (bar=0x22298,
last=4294967295) at ../../../gomp/libgomp/config/posix/bar.c:92
#3 0x000202f8 in gomp_team_start (fn=0x2a08 <main.omp_fn.0>,
data=0x0, nthreads=2, work_share=0x0) at ../../../gomp/libgomp/team.c:
293
#4 0x000029e0 in main (argc=1, argv=0xbffff714) at omp_hello.c:33
Thanks,
Walter Szeliga