[Linux-ia64] Bug report: 4-threaded program gets seg. fault on malloc, on linu

[Linux-ia64] Bug report: 4-threaded program gets seg. fault on malloc, on linu

[Robboy, David G]

I have reported this on bugzilla also, Bug #42354.  I don't know whether it
is
a kernel bug, libc, or libpthread.
The attached program spawns 3 new threads, and each of the 4 threads does a
malloc.  Run it on a 4P Lion.
On Linux kernel R2.4.3 (Red Hat release 7.0.98), it aborts with a
segmentation fault.  The same binary executable runs correctly on a R2.4.1
kernel.


#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>   
#include <asm/page.h>

#define MAXPROCS        4

void SlaveStart();

typedef struct
{
        volatile int bt_count0;
        volatile int bt_count1;
} barrier_t;

static pthread_mutex_t barrier_lock;
pthread_mutex_t (idlock);
int id = 0;
barrier_t start;
barrier_t end;
static int threadno = 0;
static pthread_t thread[MAXPROCS];


void
init_barrier(barrier_t *barr)
{
	pthread_mutex_init(&(barrier_lock), (const pthread_mutexattr_t *)0);
	barr->bt_count0 =  barr->bt_count1 = 0;
}

void
wait_barrier(barrier_t *barr, int nprocs)
{
	int rc;

	/* Two barriers guarantee that no one comes around to the barrier
	 * again before everyone is out if it, even if there are long
	 * delays in the kernel.
 	 */
	rc = pthread_mutex_lock(&barrier_lock);
	if (barr->bt_count0 = nprocs)
		barr->bt_count0 = 1;
	else
		++barr->bt_count0;
	rc = pthread_mutex_unlock(&barrier_lock);
	while (barr->bt_count0 < nprocs){
		;
	}

	rc = pthread_mutex_lock(&barrier_lock);
	/* If this has been called before, re-initialize the counter */
	if (barr->bt_count1 = nprocs)
		barr->bt_count1 = 1;
	else
		++barr->bt_count1;
	rc = pthread_mutex_unlock(&barrier_lock);
	while (barr->bt_count1 < nprocs){
		;
	}
}

main(argc, argv)

int argc;
char *argv;

{
  int i; 
  int j; 
  int c;
  int status;
  pthread_attr_t *attr = 0;

  init_barrier(&start);
  init_barrier(&end);

  for (i=1; i<MAXPROCS; i++) {
    status = pthread_create(&thread[threadno++], attr,(void
*)(SlaveStart),(void *)0);

  }
  SlaveStart();


  {exit(0);};
}


void SlaveStart()
{
  int i;
  int j;
  int MyNum;
  double error;
  double *upriv;
  int initdone; 
  int finish; 
  int l_transtime=0;
  int MyFirst; 
  int MyLast;

  {pthread_mutex_lock(&(idlock));};
    MyNum = id;
    id++;
  {pthread_mutex_unlock(&(idlock));}; 



  {wait_barrier((barrier_t *)&(start), (MAXPROCS));};

printf("Calling malloc: %d\n", MyNum);
  upriv = (double *) malloc(2*(28000000-1)*sizeof(double));  
  if (upriv = NULL) {
    fprintf(stderr,"Proc %d could not malloc memory for upriv\n",MyNum);
    exit(-1);
  }
printf("Called malloc: %d\n", MyNum);
  {wait_barrier((barrier_t *)&(end), (MAXPROCS));};
}

Re: [Linux-ia64] Bug report: 4-threaded program gets seg. fault on malloc, on linu x R2.4.3.

[Dan Pop]

On Fri, 25 May 2001, Robboy, David G wrote:

> I have reported this on bugzilla also, Bug #42354.  I don't know whether it
> is a kernel bug, libc, or libpthread.

More likely, a problem with your system.

> The attached program spawns 3 new threads, and each of the 4 threads does a
> malloc.  Run it on a 4P Lion.
> On Linux kernel R2.4.3 (Red Hat release 7.0.98), it aborts with a
> segmentation fault.  The same binary executable runs correctly on a R2.4.1
> kernel.

I couldn't reproduce your problem, despite having exactly the same
hardware and software configuration:

    pcpole67:~ 0 6> uname -a
    Linux pcpole67 2.4.3-2.10.1smp #1 SMP Fri Apr 20 12:10:00 EDT 2001 ia64 unknown
    pcpole67:~ 0 7> cat /etc/issue

    Red Hat Linux release 7.0.98 (Wolverine)
    Kernel 2.4.3-2.10.1smp on a 4-processor ia64

    pcpole67:~ 0 8> gcc foo.c -lpthread
    pcpole67:~ 0 9> ./a.out
    Calling malloc: 0
    Calling malloc: 3
    Called malloc: 0
    Called malloc: 3
    Calling malloc: 1
    Calling malloc: 2
    Called malloc: 1
    Called malloc: 2
    pcpole67:~ 0 10> 

The box has a vanilla Red Hat release 7.0.98 installation.

> main(argc, argv)
> 
> int argc;
> char *argv;
  ^^^^^^^^^^
If you want to define main in this antique fashion, at least do it right.

Dan

Re: [Linux-ia64] Bug report: 4-threaded program gets seg. fault on malloc, on linu

[David Mosberger]

>>>>> On Fri, 25 May 2001 16:17:37 -0700, "Robboy, David G" <david.g.robboy@intel.com> said:

  David.R> I have reported this on bugzilla also, Bug #42354.  I don't
  David.R> know whether it is a kernel bug, libc, or libpthread.  The
  David.R> attached program spawns 3 new threads, and each of the 4
  David.R> threads does a malloc.  Run it on a 4P Lion.  On Linux
  David.R> kernel R2.4.3 (Red Hat release 7.0.98), it aborts with a
  David.R> segmentation fault.  The same binary executable runs
  David.R> correctly on a R2.4.1 kernel.

You didn't say how you compiled the program.  Let's assume you used
"gcc -O2 -pthread": for what it's worth, this works fine here, both on
Wolverine and Guinness.  In both cases with kernel 2.4.4 and on
Wolverine I'm using glibc-2.2.2-10.

	--david

Re: [Linux-ia64] Bug report: 4-threaded program gets seg. fault on malloc, on linu x R2.4.3.

[Andreas Schwab]

"Robboy, David G" <david.g.robboy@intel.com> writes:

|> I have reported this on bugzilla also, Bug #42354.  I don't know whether it
|> is
|> a kernel bug, libc, or libpthread.
|> The attached program spawns 3 new threads, and each of the 4 threads does a
|> malloc.  Run it on a 4P Lion.
|> On Linux kernel R2.4.3 (Red Hat release 7.0.98), it aborts with a
|> segmentation fault.  The same binary executable runs correctly on a R2.4.1
|> kernel.

I have no problem running it with 2.4.4 on SuSE 7.2.

Andreas.

-- 
Andreas Schwab                                  "And now for something
SuSE Labs                                        completely different."
Andreas.Schwab@suse.de
SuSE GmbH, Schanzäckerstr. 10, D-90443 Nürnberg
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