SUMMARY: memory testing program

Thanks for the help.  Things that were recommended:

1 - I liked this most, but it doesn't work on my Sun clone / autoclient. :-(
  - one might use sum instead of wc, or kmem instead of mem.

# while true; do
> wc -c /dev/mem &
> wc -c /dev/mem &
> wc -c /dev/mem &
> wc -c /dev/mem &
> sleep 10 &
> done

2 - Sun VTS  available from www.sun.com.
  - downloaded, but not used yet.

3 - prom memory test ... seems not to be available on the clone proms. :-(

4 - eeprom: setenv diag-switch=true
  - on this box, it displays memory banks / sizes, but does not test.  :-(

5 - ftp://playground.sun.com/pub/memtool.
  - downloaded, but not tested yet.

Thanks for all your help.  The only reason I have not tested any of the tools
yet as I was having too much fun abusing my system with a small test program
I was writing.  Interesting learning exercise; I've attached that code below.
Using it never revealed the problem, so it might not be sufficient ... or
as someone suggested it could be a sporadic CPU problem.  Hope not.

Thanks again,
Don


#define __EXTENSIONS__

#include <malloc.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>

#define MAXLONGLONG	(((unsigned long) (-1)) >> 1)
#define MINLONGLONG	(((unsigned long) (-1)) ^ MAXLONGLONG)

void *malloc_and_lock(size_t *size)
{
	void *ptr, *res;
	size_t min;

	min = sysconf(_SC_PAGESIZE);
	*size = min * 100*1024;			/* 100k mem pages */

	if((res = alloca(min)) == NULL)		/* reserve stack for printf */
		return(NULL);

	while(*size > min)
	{
		if((ptr = valloc(*size)) != NULL)	/* valloc OK */
		{
			if(mlock(ptr, *size) == 0)	/* mlock OK */
				return(ptr);		/* frees res */
			else
				free(ptr);
		}

		*size >>= 1;			/* valloc() or mlock() failed */
						/* reduce size and try again */
	}

	return(NULL);				/* frees res */
}

int main()
{
	long long *check, msb, not_msb;
	void *ptr;
	size_t size, i, nel, sum = 0;

	while(1)
	{
		if((ptr = malloc_and_lock(&size)) == NULL)
			break;

		sum += size;

		printf("largest locakable block is %d bytes\n", size);
		fflush(stdout);

		nel = size / sizeof(*check);
		printf("%d long longs\n", nel);
		fflush(stdout);

		check = ptr;
		not_msb = MAXLONGLONG;	/* odd parity, all but MSB on */
		msb = MINLONGLONG;	/* odd parity, only MSB on */

		for(i = 0; i < nel; ++i)
		{
			check[i] = 0;		/* even parity, all bits on */
			check[i] = -1;		/* even parity, all bits off */

			check[i] = not_msb;	/* odd parity */
			check[i] = msb;
			if((i & 4095) == 0)
				printf("%d\r", i);
		}

		printf("done                    \n");
		fflush(stdout);
	}

	printf("checked %d bytes of RAM\n", sum);
	fflush(stdout);
	return(0);				/* unlocks and frees mem */
}