We are experiencing a problem that is unique to the Linux S390 systems running
RedHat (xSeries running RedHat are ok).  When the workloads start they do a
bunch of  pthread_creates (various by type of workload started) .  Each thread
will run until it is terminated by the user or an error is encountered.  When
attempting to create the 103 thread, pthread_create fails with a return code of
12 (ENOMEM).  I've attached a 'c' program that reproduces the failure.  The
function that is invoked on the pthread_create is not longed lived (just a
simple loop).  I compile it with gcc -lpthread -g -o mythread mythread.c . 

#ifndef _OPEN_THREADS
  #define _OPEN_THREADS
#endif
#define _POSIX_SOURCE
#define _POSIX_C_SOURCE 3
#define __EXTENSIONS__
#include <pthread.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>

typedef struct my_struct
{
   pthread_t run_id;
} my_struct;

void *runit(void *arg);

int main(int argc, char **argv)
{
  int            rc = 0;
  register unsigned int lp_cnt;
  my_struct      parm;
  pthread_attr_t attr;
  pthread_t      thread_id = pthread_self();


  pthread_attr_init(&attr);
  pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

  for(lp_cnt = 1; lp_cnt < 0xffff; lp_cnt++)
  {
     parm.run_id = lp_cnt;
     rc = pthread_create(&thread_id, &attr, runit, (void *)&parm);

     if (rc != 0)
     {
       printf("bad rc %d from pthread_create on run_id %d\n", rc, lp_cnt);
       exit(-1);
     }
  }
}

void *runit(void *arg)
{
   my_struct *parm = (my_struct *)arg;
   register unsigned int lp_cnt;

   printf("runit started for run_id %d\n", parm->run_id);
   for(lp_cnt = 0; lp_cnt < 0xffffffff; lp_cnt++);
   printf("runit ended for run_id %d\n", parm->run_id);
   fflush(stdout);
}